Pentagone régulier - Construction de Ptolémée à partir d'une des extrémités du diamètre de base
Author: Patrice Debart

A = (5, 0)
O = (0, 0)
A' = Mirror(A, O)
K = Midpoint(O, A')
c = Circle(O, A)
B' = Rotate(A, 90.0°, O)
c_2 = Circle(K, B')
AA' = Segment(A, A')
KB' = Segment(K, B')
OB' = Segment(O, B')
U = Intersect(c_2, AA', 1.0)
UB' = Segment(U, B')
a_2 = CircleArc(K, U, B')
d = LineBisector(O, U)
B = Intersect(c, d, 2.0)
F = Intersect(c, d, 1.0)
c_3 = Circle(B, A)
C = Intersect(c, c_3, 2.0)
E = Mirror(C, AA')
AB = Segment(A, B)
BC = Segment(B, C)
CE = Segment(C, E)
EF = Segment(E, F)
FA = Segment(F, A)