id
string
topic
string
difficulty
int64
problem_statement
string
solution_paths
list
reconciliation
dict
error_catalogue
list
conceptual_takeaway
string
math-011001
Euclidean Geometry: Heron's Formula
6
Question: A triangle has side lengths $a=8$, $b=45$, $c=49$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clearly state the ...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{8+45+49}{2}=51$.", "Step 2: Compute $s-a=43$, $s-b=6$, $s-c=2$.", "Step 3: Multiply: $s(s-a)(s-b)(s-c)=26316$.", ...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\sqrt{26316}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computations...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{26316}$.)
math-011002
Geometry: Area Invariants
6
Work carefully and justify each inference: A triangle has side lengths $a=40$, $b=55$, $c=59$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you u...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{40+55+59}{2}=77$.", "Step 2: Compute $s-a=37$, $s-b=22$, $s-c=18$.", "Step 3: Multiply: $s(s-a)(s-b)(s-c)=1128204$...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\sqrt{1128204}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computations mus...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Takeaway: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{1128204}$.)
math-011003
Geometry: Area Invariants
6
Show all reasoning: A triangle has side lengths $a=14$, $b=49$, $c=58$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clearly...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{14+49+58}{2}=\\frac{121}{2}$.", "Step 2: Compute $s-a=\\frac{93}{2}$, $s-b=\\frac{23}{2}$, $s-c=\\frac{5}{2}$.", "...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\sqrt{\\frac{1294095}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computati...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Key idea: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{1294095}$.)
math-011004
Geometry: Side-Length Data to Area
6
Answer with a short justification: A triangle has side lengths $a=16$, $b=44$, $c=49$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coord...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{16+44+49}{2}=\\frac{109}{2}$.", "Step 2: Compute $s-a=\\frac{77}{2}$, $s-b=\\frac{21}{2}$, $s-c=\\frac{11}{2}$.", ...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\sqrt{\\frac{1938783}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both com...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{1938783}$.)
math-011005
Geometry: Area Invariants
6
Answer with a short justification: A triangle has side lengths $a=12$, $b=36$, $c=46$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coord...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{12+36+46}{2}=47$.", "Step 2: Compute $s-a=35$, $s-b=11$, $s-c=1$.", "Step 3: Multiply: $s(s-a)(s-b)(s-c)=18095$.",...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\sqrt{18095}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computations must ...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{18095}$.)
math-011006
Geometry: Area Invariants
6
Do not skip justification steps: A triangle has side lengths $a=35$, $b=47$, $c=51$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordin...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(51,0)$ so $AB=c=51$.", "Step 2: ...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\sqrt{\\frac{10130211}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computat...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{10130211}$.)
math-011007
Euclidean Geometry: Heron's Formula
6
Show all reasoning: A triangle has side lengths $a=23$, $b=41$, $c=45$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clearly...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{23+41+45}{2}=\\frac{109}{2}$.", "Step 2: Compute $s-a=\\frac{63}{2}$, $s-b=\\frac{27}{2}$, $s-c=\\frac{19}{2}$.", ...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\sqrt{\\frac{3522771}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid ...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Takeaway: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{3522771}$.)
math-011008
Geometry: Side-Length Data to Area
6
Answer with a short justification: A triangle has side lengths $a=10$, $b=45$, $c=50$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coord...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{10+45+50}{2}=\\frac{105}{2}$.", "Step 2: Compute $s-a=\\frac{85}{2}$, $s-b=\\frac{15}{2}$, $s-c=\\frac{5}{2}$.", "...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\sqrt{\\frac{669375}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computatio...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Takeaway: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{669375}$.)
math-011009
Geometry: Side-Length Data to Area
6
Track quantifiers carefully: A triangle has side lengths $a=35$, $b=40$, $c=51$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(51,0)$ so $AB=c=51$.", "Step 2: ...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\sqrt{486864}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computations must...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Key idea: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011010
Geometry: Side-Length Data to Area
6
Determine the requested value: A triangle has side lengths $a=49$, $b=60$, $c=60$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinat...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(60,0)$ so $AB=c=60$.", "Step 2: ...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\sqrt{\\frac{28809599}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{28809599}$.)
math-011011
Geometry: Side-Length Data to Area
6
Track quantifiers carefully: A triangle has side lengths $a=47$, $b=48$, $c=48$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(48,0)$ so $AB=c=48$.", "Step 2: ...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\sqrt{\\frac{15478463}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both co...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Core principle: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{15478463}$.)
math-011012
Coordinate Geometry: Base–Height via Distances
6
Where appropriate, name the theorem you use: A triangle has side lengths $a=38$, $b=39$, $c=52$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{38+39+52}{2}=\\frac{129}{2}$.", "Step 2: Compute $s-a=\\frac{53}{2}$, $s-b=\\frac{51}{2}$, $s-c=\\frac{25}{2}$.", ...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\sqrt{\\frac{8717175}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both com...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{8717175}$.)
math-011013
Coordinate Geometry: Base–Height via Distances
6
Make each step logically reversible (or explain if not): A triangle has side lengths $a=21$, $b=24$, $c=42$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side leng...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{21+24+42}{2}=\\frac{87}{2}$.", "Step 2: Compute $s-a=\\frac{45}{2}$, $s-b=\\frac{39}{2}$, $s-c=\\frac{3}{2}$.", "S...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\sqrt{\\frac{458055}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computatio...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Key idea: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{458055}$.)
math-011014
Euclidean Geometry: Heron's Formula
6
Give an answer and a quick verification: A triangle has side lengths $a=36$, $b=38$, $c=59$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(59,0)$ so $AB=c=59$.", "Step 2: ...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\sqrt{\\frac{6936615}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant und...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Key idea: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{6936615}$.)
math-011015
Geometry: Area Invariants
6
Determine the requested value: A triangle has side lengths $a=36$, $b=54$, $c=58$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinat...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{36+54+58}{2}=74$.", "Step 2: Compute $s-a=38$, $s-b=20$, $s-c=16$.", "Step 3: Multiply: $s(s-a)(s-b)(s-c)=899840$....
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\sqrt{899840}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computation...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Takeaway: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011016
Geometry: Area Invariants
6
Proceed methodically: A triangle has side lengths $a=21$, $b=56$, $c=58$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clear...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(58,0)$ so $AB=c=58$.", "Step 2: ...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\sqrt{\\frac{5486535}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computati...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Takeaway: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{5486535}$.)
math-011017
Geometry: Side-Length Data to Area
6
Warm-up: A triangle has side lengths $a=9$, $b=14$, $c=17$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clearly state the p...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(17,0)$ so $AB=c=17$.", "Step 2: ...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\sqrt{3960}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computations must m...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{3960}$.)
math-011018
Euclidean Geometry: Heron's Formula
6
Answer using clear logical steps: A triangle has side lengths $a=31$, $b=54$, $c=56$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordi...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{31+54+56}{2}=\\frac{141}{2}$.", "Step 2: Compute $s-a=\\frac{79}{2}$, $s-b=\\frac{33}{2}$, $s-c=\\frac{29}{2}$.", ...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\sqrt{\\frac{10660023}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both co...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Takeaway: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011019
Geometry: Area Invariants
6
Complete the analysis: A triangle has side lengths $a=18$, $b=34$, $c=34$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clea...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{18+34+34}{2}=43$.", "Step 2: Compute $s-a=25$, $s-b=9$, $s-c=9$.", "Step 3: Multiply: $s(s-a)(s-b)(s-c)=87075$.", ...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\sqrt{87075}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid ...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Key idea: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{87075}$.)
math-011020
Coordinate Geometry: Base–Height via Distances
6
Carefully track domains: A triangle has side lengths $a=21$, $b=36$, $c=49$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, cl...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{21+36+49}{2}=53$.", "Step 2: Compute $s-a=32$, $s-b=17$, $s-c=4$.", "Step 3: Multiply: $s(s-a)(s-b)(s-c)=115328$."...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\sqrt{115328}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computation...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Key idea: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011021
Geometry: Side-Length Data to Area
6
Write the solution set clearly: A triangle has side lengths $a=26$, $b=43$, $c=54$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordina...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(54,0)$ so $AB=c=54$.", "Step 2: ...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\sqrt{\\frac{4846815}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid ...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011022
Geometry: Side-Length Data to Area
6
Provide both a computational and a conceptual explanation: A triangle has side lengths $a=26$, $b=34$, $c=53$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side le...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{26+34+53}{2}=\\frac{113}{2}$.", "Step 2: Compute $s-a=\\frac{61}{2}$, $s-b=\\frac{45}{2}$, $s-c=\\frac{7}{2}$.", "...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\sqrt{\\frac{2171295}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid ...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{2171295}$.)
math-011023
Euclidean Geometry: Heron's Formula
6
Solve and include a self-check: A triangle has side lengths $a=19$, $b=25$, $c=31$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordina...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(31,0)$ so $AB=c=31$.", "Step 2: ...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\sqrt{\\frac{901875}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both comp...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Core principle: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{901875}$.)
math-011024
Geometry: Side-Length Data to Area
6
Use two approaches if possible: A triangle has side lengths $a=30$, $b=40$, $c=48$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordina...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(48,0)$ so $AB=c=48$.", "Step 2: ...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\sqrt{357599}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computation...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Core principle: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011025
Coordinate Geometry: Base–Height via Distances
6
Exercise: A triangle has side lengths $a=39$, $b=41$, $c=55$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clearly state the...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(55,0)$ so $AB=c=55$.", "Step 2: ...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\sqrt{\\frac{10195875}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant un...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Core principle: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{10195875}$.)
math-011026
Geometry: Side-Length Data to Area
6
Find the exact value: A triangle has side lengths $a=18$, $b=44$, $c=46$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clear...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{18+44+46}{2}=54$.", "Step 2: Compute $s-a=36$, $s-b=10$, $s-c=8$.", "Step 3: Multiply: $s(s-a)(s-b)(s-c)=155520$."...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\sqrt{155520}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions,...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Core principle: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{155520}$.)
math-011027
Geometry: Area Invariants
6
Challenge: A triangle has side lengths $a=15$, $b=41$, $c=49$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clearly state th...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{15+41+49}{2}=\\frac{105}{2}$.", "Step 2: Compute $s-a=\\frac{75}{2}$, $s-b=\\frac{23}{2}$, $s-c=\\frac{7}{2}$.", "...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\sqrt{\\frac{1267875}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid ...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011028
Geometry: Side-Length Data to Area
6
Give a fully justified solution: A triangle has side lengths $a=44$, $b=44$, $c=48$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordin...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{44+44+48}{2}=68$.", "Step 2: Compute $s-a=24$, $s-b=24$, $s-c=20$.", "Step 3: Multiply: $s(s-a)(s-b)(s-c)=783360$....
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\sqrt{783360}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computations must...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Takeaway: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{783360}$.)
math-011029
Geometry: Area Invariants
6
Checkpoint: A triangle has side lengths $a=36$, $b=49$, $c=59$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clearly state t...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(59,0)$ so $AB=c=59$.", "Step 2: ...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\sqrt{775008}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Key idea: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011030
Geometry: Area Invariants
6
Track units/moduli carefully: A triangle has side lengths $a=31$, $b=52$, $c=60$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinate...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{31+52+60}{2}=\\frac{143}{2}$.", "Step 2: Compute $s-a=\\frac{81}{2}$, $s-b=\\frac{39}{2}$, $s-c=\\frac{23}{2}$.", ...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\sqrt{\\frac{10389951}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computat...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{10389951}$.)
math-011031
Coordinate Geometry: Base–Height via Distances
6
Indicate where a theorem is used: A triangle has side lengths $a=36$, $b=45$, $c=48$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordi...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{36+45+48}{2}=\\frac{129}{2}$.", "Step 2: Compute $s-a=\\frac{57}{2}$, $s-b=\\frac{39}{2}$, $s-c=\\frac{33}{2}$.", ...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\sqrt{\\frac{9463311}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid ...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Takeaway: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{9463311}$.)
math-011032
Coordinate Geometry: Base–Height via Distances
6
Be explicit about assumptions: A triangle has side lengths $a=13$, $b=40$, $c=41$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinat...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(41,0)$ so $AB=c=41$.", "Step 2: ...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\sqrt{67116}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid ...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Core principle: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011033
Coordinate Geometry: Base–Height via Distances
6
Solve and justify each step: A triangle has side lengths $a=15$, $b=33$, $c=37$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(37,0)$ so $AB=c=37$.", "Step 2: ...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\sqrt{\\frac{977075}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computatio...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Core principle: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{977075}$.)
math-011034
Geometry: Area Invariants
6
Where appropriate, name the theorem you use: A triangle has side lengths $a=37$, $b=39$, $c=55$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{37+39+55}{2}=\\frac{131}{2}$.", "Step 2: Compute $s-a=\\frac{57}{2}$, $s-b=\\frac{53}{2}$, $s-c=\\frac{21}{2}$.", ...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\sqrt{\\frac{8310771}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computati...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Key idea: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011035
Geometry: Area Invariants
6
Try to avoid pattern-matching; explain why: A triangle has side lengths $a=25$, $b=42$, $c=59$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you ...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(59,0)$ so $AB=c=59$.", "Step 2: ...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\sqrt{201096}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Key idea: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{201096}$.)
math-011036
Geometry: Side-Length Data to Area
6
State any required conditions first: A triangle has side lengths $a=29$, $b=38$, $c=47$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coo...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{29+38+47}{2}=57$.", "Step 2: Compute $s-a=28$, $s-b=19$, $s-c=10$.", "Step 3: Multiply: $s(s-a)(s-b)(s-c)=303240$....
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\sqrt{303240}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{303240}$.)
math-011037
Coordinate Geometry: Base–Height via Distances
6
Work carefully and justify each inference: A triangle has side lengths $a=10$, $b=35$, $c=41$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you u...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{10+35+41}{2}=43$.", "Step 2: Compute $s-a=33$, $s-b=8$, $s-c=2$.", "Step 3: Multiply: $s(s-a)(s-b)(s-c)=22704$.", ...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\sqrt{22704}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, ...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011038
Geometry: Area Invariants
6
Give reasoning, not just computation: A triangle has side lengths $a=26$, $b=44$, $c=45$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use co...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(45,0)$ so $AB=c=45$.", "Step 2: ...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\sqrt{\\frac{4890375}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computati...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Takeaway: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011039
Geometry: Area Invariants
6
Compute the requested quantity: A triangle has side lengths $a=54$, $b=57$, $c=60$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordina...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{54+57+60}{2}=\\frac{171}{2}$.", "Step 2: Compute $s-a=\\frac{63}{2}$, $s-b=\\frac{57}{2}$, $s-c=\\frac{51}{2}$.", ...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\sqrt{\\frac{31317111}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Core principle: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{31317111}$.)
math-011040
Geometry: Side-Length Data to Area
6
Carefully track domains: A triangle has side lengths $a=32$, $b=34$, $c=35$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, cl...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{32+34+35}{2}=\\frac{101}{2}$.", "Step 2: Compute $s-a=\\frac{37}{2}$, $s-b=\\frac{33}{2}$, $s-c=\\frac{31}{2}$.", ...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\sqrt{\\frac{3822951}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computati...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Core principle: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{3822951}$.)
math-011041
Geometry: Area Invariants
6
Find the exact value: A triangle has side lengths $a=24$, $b=35$, $c=58$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clear...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(58,0)$ so $AB=c=58$.", "Step 2: ...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\sqrt{\\frac{379431}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant unde...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{379431}$.)
math-011042
Euclidean Geometry: Heron's Formula
6
Solve (and briefly cross-validate): A triangle has side lengths $a=10$, $b=50$, $c=58$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coor...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{10+50+58}{2}=59$.", "Step 2: Compute $s-a=49$, $s-b=9$, $s-c=1$.", "Step 3: Multiply: $s(s-a)(s-b)(s-c)=26019$.", ...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\sqrt{26019}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, ...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{26019}$.)
math-011043
Geometry: Side-Length Data to Area
6
Carefully track domains: A triangle has side lengths $a=9$, $b=43$, $c=48$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, cle...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{9+43+48}{2}=50$.", "Step 2: Compute $s-a=41$, $s-b=7$, $s-c=2$.", "Step 3: Multiply: $s(s-a)(s-b)(s-c)=28700$.", ...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\sqrt{28700}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, ...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{28700}$.)
math-011044
Geometry: Side-Length Data to Area
6
Provide a rigorous solution: A triangle has side lengths $a=52$, $b=54$, $c=57$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{52+54+57}{2}=\\frac{163}{2}$.", "Step 2: Compute $s-a=\\frac{59}{2}$, $s-b=\\frac{55}{2}$, $s-c=\\frac{49}{2}$.", ...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\sqrt{\\frac{25917815}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant un...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{25917815}$.)
math-011045
Euclidean Geometry: Heron's Formula
6
Proceed methodically: A triangle has side lengths $a=23$, $b=41$, $c=43$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clear...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{23+41+43}{2}=\\frac{107}{2}$.", "Step 2: Compute $s-a=\\frac{61}{2}$, $s-b=\\frac{25}{2}$, $s-c=\\frac{21}{2}$.", ...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\sqrt{\\frac{3426675}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both com...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Core principle: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{3426675}$.)
math-011046
Geometry: Area Invariants
6
Find the exact value: A triangle has side lengths $a=23$, $b=50$, $c=56$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clear...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(56,0)$ so $AB=c=56$.", "Step 2: ...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\sqrt{\\frac{5278551}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant und...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011047
Geometry: Area Invariants
6
Try to avoid pattern-matching; explain why: A triangle has side lengths $a=17$, $b=51$, $c=55$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you ...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(55,0)$ so $AB=c=55$.", "Step 2: ...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\sqrt{\\frac{2988531}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid ...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{2988531}$.)
math-011048
Geometry: Side-Length Data to Area
6
Explain why your operations are valid: A triangle has side lengths $a=21$, $b=32$, $c=49$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use c...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(49,0)$ so $AB=c=49$.", "Step 2: ...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\sqrt{58140}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid ...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Takeaway: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{58140}$.)
math-011049
Euclidean Geometry: Heron's Formula
6
Use two approaches if possible: A triangle has side lengths $a=43$, $b=49$, $c=58$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordina...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(58,0)$ so $AB=c=58$.", "Step 2: ...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\sqrt{1060800}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigi...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{1060800}$.)
math-011050
Geometry: Side-Length Data to Area
6
Solve (and briefly cross-validate): A triangle has side lengths $a=26$, $b=27$, $c=49$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coor...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(49,0)$ so $AB=c=49$.", "Step 2: ...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\sqrt{61200}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computations...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Key idea: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{61200}$.)
math-011051
Geometry: Side-Length Data to Area
6
Solve with verification: A triangle has side lengths $a=17$, $b=36$, $c=43$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, cl...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(43,0)$ so $AB=c=43$.", "Step 2: ...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\sqrt{89280}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computations must ...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Takeaway: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011052
Geometry: Side-Length Data to Area
6
Exercise: A triangle has side lengths $a=6$, $b=27$, $c=30$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clearly state the ...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(30,0)$ so $AB=c=30$.", "Step 2: ...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\sqrt{\\frac{86751}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Core principle: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011053
Geometry: Area Invariants
6
Answer with a short justification: A triangle has side lengths $a=23$, $b=36$, $c=43$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coord...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(43,0)$ so $AB=c=43$.", "Step 2: ...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\sqrt{171360}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computation...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{171360}$.)
math-011054
Euclidean Geometry: Heron's Formula
6
Task: A triangle has side lengths $a=40$, $b=43$, $c=55$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clearly state the poi...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(55,0)$ so $AB=c=55$.", "Step 2: ...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\sqrt{728364}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions,...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Core principle: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{728364}$.)
math-011055
Geometry: Side-Length Data to Area
6
Checkpoint: A triangle has side lengths $a=25$, $b=48$, $c=49$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clearly state t...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(49,0)$ so $AB=c=49$.", "Step 2: ...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\sqrt{342576}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computation...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Core principle: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011056
Euclidean Geometry: Heron's Formula
6
Track units/moduli carefully: A triangle has side lengths $a=12$, $b=45$, $c=49$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinate...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{12+45+49}{2}=53$.", "Step 2: Compute $s-a=41$, $s-b=8$, $s-c=4$.", "Step 3: Multiply: $s(s-a)(s-b)(s-c)=69536$.", ...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\sqrt{69536}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computations...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Key idea: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{69536}$.)
math-011057
Coordinate Geometry: Base–Height via Distances
6
Compute the requested quantity: A triangle has side lengths $a=13$, $b=35$, $c=36$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordina...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{13+35+36}{2}=42$.", "Step 2: Compute $s-a=29$, $s-b=7$, $s-c=6$.", "Step 3: Multiply: $s(s-a)(s-b)(s-c)=51156$.", ...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\sqrt{51156}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computations must ...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Key idea: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{51156}$.)
math-011058
Coordinate Geometry: Base–Height via Distances
6
Keep the final answer in boxed form: A triangle has side lengths $a=44$, $b=54$, $c=58$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coo...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(58,0)$ so $AB=c=58$.", "Step 2: ...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\sqrt{1272960}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computatio...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{1272960}$.)
math-011059
Geometry: Side-Length Data to Area
6
Give a fully justified solution: A triangle has side lengths $a=21$, $b=47$, $c=55$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordin...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{21+47+55}{2}=\\frac{123}{2}$.", "Step 2: Compute $s-a=\\frac{81}{2}$, $s-b=\\frac{29}{2}$, $s-c=\\frac{13}{2}$.", ...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\sqrt{\\frac{3756051}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both com...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Takeaway: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{3756051}$.)
math-011060
Geometry: Side-Length Data to Area
6
Solve with verification: A triangle has side lengths $a=32$, $b=38$, $c=57$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, cl...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{32+38+57}{2}=\\frac{127}{2}$.", "Step 2: Compute $s-a=\\frac{63}{2}$, $s-b=\\frac{51}{2}$, $s-c=\\frac{13}{2}$.", ...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\sqrt{\\frac{5304663}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computati...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Key idea: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011061
Euclidean Geometry: Heron's Formula
6
Proceed methodically: A triangle has side lengths $a=16$, $b=42$, $c=56$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clear...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{16+42+56}{2}=57$.", "Step 2: Compute $s-a=41$, $s-b=15$, $s-c=1$.", "Step 3: Multiply: $s(s-a)(s-b)(s-c)=35055$.",...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\sqrt{35055}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computations...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Key idea: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{35055}$.)
math-011062
Coordinate Geometry: Base–Height via Distances
6
Proceed methodically: A triangle has side lengths $a=39$, $b=52$, $c=59$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clear...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(59,0)$ so $AB=c=59$.", "Step 2: ...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\sqrt{993600}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computations must...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011063
Coordinate Geometry: Base–Height via Distances
6
Give a theorem-based solution: A triangle has side lengths $a=35$, $b=42$, $c=60$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinat...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(60,0)$ so $AB=c=60$.", "Step 2: ...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\sqrt{\\frac{8270279}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computati...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Takeaway: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011064
Geometry: Side-Length Data to Area
6
Derive the result step-by-step: A triangle has side lengths $a=20$, $b=46$, $c=52$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordina...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(52,0)$ so $AB=c=52$.", "Step 2: ...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\sqrt{209391}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Key idea: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{209391}$.)
math-011065
Coordinate Geometry: Base–Height via Distances
6
Exercise: A triangle has side lengths $a=41$, $b=43$, $c=52$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clearly state the...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{41+43+52}{2}=68$.", "Step 2: Compute $s-a=27$, $s-b=25$, $s-c=16$.", "Step 3: Multiply: $s(s-a)(s-b)(s-c)=734400$....
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\sqrt{734400}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Key idea: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{734400}$.)
math-011066
Coordinate Geometry: Base–Height via Distances
6
Answer with a short justification: A triangle has side lengths $a=41$, $b=55$, $c=57$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coord...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{41+55+57}{2}=\\frac{153}{2}$.", "Step 2: Compute $s-a=\\frac{71}{2}$, $s-b=\\frac{43}{2}$, $s-c=\\frac{39}{2}$.", ...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\sqrt{\\frac{18217251}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant un...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Key idea: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011067
Euclidean Geometry: Heron's Formula
6
Challenge: A triangle has side lengths $a=34$, $b=44$, $c=48$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clearly state th...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{34+44+48}{2}=63$.", "Step 2: Compute $s-a=29$, $s-b=19$, $s-c=15$.", "Step 3: Multiply: $s(s-a)(s-b)(s-c)=520695$....
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\sqrt{520695}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computation...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011068
Coordinate Geometry: Base–Height via Distances
6
Make each step logically reversible (or explain if not): A triangle has side lengths $a=22$, $b=28$, $c=36$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side leng...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(36,0)$ so $AB=c=36$.", "Step 2: ...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\sqrt{94815}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, ...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011069
Geometry: Area Invariants
6
Track units/moduli carefully: A triangle has side lengths $a=27$, $b=42$, $c=48$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinate...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(48,0)$ so $AB=c=48$.", "Step 2: ...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\sqrt{\\frac{5108103}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid ...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011070
Euclidean Geometry: Heron's Formula
6
Carefully track domains: A triangle has side lengths $a=29$, $b=47$, $c=58$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, cl...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{29+47+58}{2}=67$.", "Step 2: Compute $s-a=38$, $s-b=20$, $s-c=9$.", "Step 3: Multiply: $s(s-a)(s-b)(s-c)=458280$."...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\sqrt{458280}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computation...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011071
Coordinate Geometry: Base–Height via Distances
6
Keep the final answer in boxed form: A triangle has side lengths $a=21$, $b=28$, $c=41$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coo...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(41,0)$ so $AB=c=41$.", "Step 2: ...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\sqrt{73440}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, ...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Takeaway: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011072
Coordinate Geometry: Base–Height via Distances
6
Try to avoid pattern-matching; explain why: A triangle has side lengths $a=46$, $b=56$, $c=58$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you ...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{46+56+58}{2}=80$.", "Step 2: Compute $s-a=34$, $s-b=24$, $s-c=22$.", "Step 3: Multiply: $s(s-a)(s-b)(s-c)=1436160$...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\sqrt{1436160}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigi...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Key idea: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{1436160}$.)
math-011073
Geometry: Side-Length Data to Area
6
Explain why your operations are valid: A triangle has side lengths $a=22$, $b=41$, $c=58$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use c...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(58,0)$ so $AB=c=58$.", "Step 2: ...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\sqrt{\\frac{1816815}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computati...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{1816815}$.)
math-011074
Euclidean Geometry: Heron's Formula
6
Task: A triangle has side lengths $a=17$, $b=33$, $c=35$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clearly state the poi...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(35,0)$ so $AB=c=35$.", "Step 2: ...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\sqrt{\\frac{1235475}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant und...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Key idea: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011075
Geometry: Side-Length Data to Area
6
Where appropriate, name the theorem you use: A triangle has side lengths $a=27$, $b=32$, $c=56$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{27+32+56}{2}=\\frac{115}{2}$.", "Step 2: Compute $s-a=\\frac{61}{2}$, $s-b=\\frac{51}{2}$, $s-c=\\frac{3}{2}$.", "...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\sqrt{\\frac{1073295}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant und...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{1073295}$.)
math-011076
Geometry: Side-Length Data to Area
6
Warm-up: A triangle has side lengths $a=24$, $b=32$, $c=39$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clearly state the ...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(39,0)$ so $AB=c=39$.", "Step 2: ...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\sqrt{\\frac{2353055}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computati...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Key idea: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{2353055}$.)
math-011077
Coordinate Geometry: Base–Height via Distances
6
Exercise: A triangle has side lengths $a=24$, $b=27$, $c=45$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clearly state the...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(45,0)$ so $AB=c=45$.", "Step 2: ...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\sqrt{72576}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid ...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Core principle: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011078
Euclidean Geometry: Heron's Formula
6
Indicate where a theorem is used: A triangle has side lengths $a=17$, $b=20$, $c=23$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordi...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(23,0)$ so $AB=c=23$.", "Step 2: ...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\sqrt{27300}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computations...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Takeaway: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011079
Geometry: Side-Length Data to Area
6
Be explicit about assumptions: A triangle has side lengths $a=10$, $b=32$, $c=33$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinat...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(33,0)$ so $AB=c=33$.", "Step 2: ...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\sqrt{\\frac{408375}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant unde...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Takeaway: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{408375}$.)
math-011080
Coordinate Geometry: Base–Height via Distances
6
Where appropriate, name the theorem you use: A triangle has side lengths $a=25$, $b=46$, $c=46$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{25+46+46}{2}=\\frac{117}{2}$.", "Step 2: Compute $s-a=\\frac{67}{2}$, $s-b=\\frac{25}{2}$, $s-c=\\frac{25}{2}$.", ...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\sqrt{\\frac{4899375}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid ...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{4899375}$.)
math-011081
Geometry: Side-Length Data to Area
6
Exercise: A triangle has side lengths $a=28$, $b=34$, $c=56$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clearly state the...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(56,0)$ so $AB=c=56$.", "Step 2: ...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\sqrt{137175}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions,...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011082
Coordinate Geometry: Base–Height via Distances
6
Track quantifiers carefully: A triangle has side lengths $a=14$, $b=49$, $c=60$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(60,0)$ so $AB=c=60$.", "Step 2: ...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\sqrt{\\frac{876375}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid m...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{876375}$.)
math-011083
Geometry: Side-Length Data to Area
6
Challenge: A triangle has side lengths $a=47$, $b=59$, $c=60$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clearly state th...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(60,0)$ so $AB=c=60$.", "Step 2: ...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\sqrt{1649376}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{1649376}$.)
math-011084
Geometry: Side-Length Data to Area
6
Write the solution set clearly: A triangle has side lengths $a=28$, $b=29$, $c=48$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordina...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{28+29+48}{2}=\\frac{105}{2}$.", "Step 2: Compute $s-a=\\frac{49}{2}$, $s-b=\\frac{47}{2}$, $s-c=\\frac{9}{2}$.", "...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\sqrt{\\frac{2176335}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant und...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Key idea: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{2176335}$.)
math-011085
Geometry: Side-Length Data to Area
6
Answer with a short justification: A triangle has side lengths $a=42$, $b=47$, $c=51$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coord...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{42+47+51}{2}=70$.", "Step 2: Compute $s-a=28$, $s-b=23$, $s-c=19$.", "Step 3: Multiply: $s(s-a)(s-b)(s-c)=856520$....
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\sqrt{856520}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Core principle: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011086
Geometry: Area Invariants
6
Question: A triangle has side lengths $a=10$, $b=12$, $c=20$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clearly state the...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{10+12+20}{2}=21$.", "Step 2: Compute $s-a=11$, $s-b=9$, $s-c=1$.", "Step 3: Multiply: $s(s-a)(s-b)(s-c)=2079$.", ...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\sqrt{2079}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computations must m...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Takeaway: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011087
Euclidean Geometry: Heron's Formula
6
Provide a rigorous solution: A triangle has side lengths $a=14$, $b=18$, $c=18$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(18,0)$ so $AB=c=18$.", "Step 2: ...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\sqrt{13475}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, ...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011088
Geometry: Side-Length Data to Area
6
Derive the result step-by-step: A triangle has side lengths $a=47$, $b=55$, $c=59$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordina...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{47+55+59}{2}=\\frac{161}{2}$.", "Step 2: Compute $s-a=\\frac{67}{2}$, $s-b=\\frac{51}{2}$, $s-c=\\frac{43}{2}$.", ...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\sqrt{\\frac{23655891}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Key idea: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011089
Coordinate Geometry: Base–Height via Distances
6
Use two approaches if possible: A triangle has side lengths $a=19$, $b=29$, $c=30$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordina...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{19+29+30}{2}=39$.", "Step 2: Compute $s-a=20$, $s-b=10$, $s-c=9$.", "Step 3: Multiply: $s(s-a)(s-b)(s-c)=70200$.",...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\sqrt{70200}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computations...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{70200}$.)
math-011090
Geometry: Area Invariants
6
Solve (and briefly cross-validate): A triangle has side lengths $a=34$, $b=38$, $c=49$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coor...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{34+38+49}{2}=\\frac{121}{2}$.", "Step 2: Compute $s-a=\\frac{53}{2}$, $s-b=\\frac{45}{2}$, $s-c=\\frac{23}{2}$.", ...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\sqrt{\\frac{6637455}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both com...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{6637455}$.)
math-011091
Geometry: Area Invariants
6
Proceed methodically: A triangle has side lengths $a=27$, $b=49$, $c=54$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clear...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(54,0)$ so $AB=c=54$.", "Step 2: ...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\sqrt{434720}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{434720}$.)
math-011092
Geometry: Area Invariants
6
Question: A triangle has side lengths $a=11$, $b=59$, $c=59$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clearly state the...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(59,0)$ so $AB=c=59$.", "Step 2: ...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\sqrt{\\frac{1670163}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both com...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011093
Coordinate Geometry: Base–Height via Distances
6
Find the exact value: A triangle has side lengths $a=21$, $b=30$, $c=31$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clear...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{21+30+31}{2}=41$.", "Step 2: Compute $s-a=20$, $s-b=11$, $s-c=10$.", "Step 3: Multiply: $s(s-a)(s-b)(s-c)=90200$."...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\sqrt{90200}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid ...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011094
Coordinate Geometry: Base–Height via Distances
6
Solve and sanity-check: A triangle has side lengths $a=33$, $b=45$, $c=55$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, cle...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(55,0)$ so $AB=c=55$.", "Step 2: ...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\sqrt{\\frac{8812979}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant und...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Key idea: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011095
Geometry: Side-Length Data to Area
6
Challenge: A triangle has side lengths $a=33$, $b=34$, $c=45$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clearly state th...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(45,0)$ so $AB=c=45$.", "Step 2: ...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\sqrt{311696}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions,...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011096
Geometry: Area Invariants
6
Solve and include a self-check: A triangle has side lengths $a=32$, $b=44$, $c=56$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordina...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(56,0)$ so $AB=c=56$.", "Step 2: ...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\sqrt{493680}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computations must...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Key idea: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{493680}$.)
math-011097
Euclidean Geometry: Heron's Formula
6
Indicate where a theorem is used: A triangle has side lengths $a=35$, $b=42$, $c=47$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordi...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{35+42+47}{2}=62$.", "Step 2: Compute $s-a=27$, $s-b=20$, $s-c=15$.", "Step 3: Multiply: $s(s-a)(s-b)(s-c)=502200$....
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\sqrt{502200}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computations must...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Key idea: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{502200}$.)
math-011098
Coordinate Geometry: Base–Height via Distances
6
Use two approaches if possible: A triangle has side lengths $a=9$, $b=36$, $c=37$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinat...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(37,0)$ so $AB=c=37$.", "Step 2: ...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\sqrt{26240}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid ...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Key idea: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check.
math-011099
Coordinate Geometry: Base–Height via Distances
6
Indicate where a theorem is used: A triangle has side lengths $a=11$, $b=38$, $c=44$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordi...
[ { "method_name": "Coordinate Geometry (Distance Constraints)", "approach": "Place one side on the $x$-axis, solve for the third vertex using distances, and compute $\\frac12\\cdot\\text{base}\\cdot\\text{height}$.", "steps": [ "Step 1: Place $A=(0,0)$ and $B=(44,0)$ so $AB=c=44$.", "Step 2: ...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\sqrt{\\frac{561255}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid m...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Key idea: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{\frac{561255}$.)
math-011100
Euclidean Geometry: Heron's Formula
6
Find the exact value: A triangle has side lengths $a=38$, $b=42$, $c=56$. (a) Compute its area using Heron's formula. (b) Give an independent derivation by placing the triangle in coordinates (base–height). (c) Explain why the two methods must agree even though one uses only side lengths. If you use coordinates, clear...
[ { "method_name": "Heron's Formula", "approach": "Compute semiperimeter $s$ and apply $[\\triangle]=\\sqrt{s(s-a)(s-b)(s-c)}$.", "steps": [ "Step 1: Semiperimeter $s=\\frac{38+42+56}{2}=68$.", "Step 2: Compute $s-a=30$, $s-b=26$, $s-c=12$.", "Step 3: Multiply: $s(s-a)(s-b)(s-c)=636480$....
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\sqrt{636480}$.\nHeron's formula is a side-length invariant. The coordinate method computes the same geometric area after embedding the triangle in the plane; since area is invariant under rigid motions, both computations must...
[ { "error_description": "Used perimeter instead of semiperimeter in Heron's formula.", "why_plausible": "The symbol $s$ is easy to confuse with the full perimeter.", "why_wrong": "Heron's formula requires $s=(a+b+c)/2$; using $a+b+c$ squares the scale incorrectly.", "which_method_catches_it": "Coordi...
Remember: The same geometric quantity can be computed from different invariants: side lengths (Heron) or coordinates (base–height). Agreement across methods is a powerful correctness check. (Here the result is $\boxed{\sqrt{636480}$.)