import OAI.Geometry.CylinderCovering.Radial.CoordinatesDefinitions namespace OAI noncomputable section open Set namespace RadialCoordinates.BarycentricSector def positiveSector (l r A : ℝ) : Set Plane := {z | ∃ t ∈ Icc l r, ∃ ρ ∈ Icc (0 : ℝ) A, z = ρ • ray t} def signedSector (l r a b : ℝ) : Set Plane := {z | ∃ t ∈ Icc l r, ∃ ρ ∈ Icc (-a) b, z = ρ • ray t} def vertices (l r A : ℝ) : Fin 3 → Plane := ![0, A • ray l, A • ray r] def perimeter (l r A : ℝ) : ℝ := dist (0 : Plane) (A • ray l) + dist (A • ray l) (A • ray r) + dist (A • ray r) 0 end RadialCoordinates.BarycentricSector end end OAI