Construction de Ptolémée du pentagone régulier
Author: Patrice Debart

A = (0, 5)
O = (0, 0)
A_2 = Rotate(A, 270.0°, O)
A' = Mirror(A_2, O)
K = Midpoint(O, A')
c = Circle(O, A_2)
c_2 = Circle(K, A)
diam = Segment(A_2, A')
KA = Segment(K, A)
OA = Segment(O, A)
U = Intersect(c_2, diam, 1.0)
UA = Segment(U, A)
a_2 = CircleArc(K, U, A)
c_3 = Circle(A, U)
B = Intersect(c, c_3, 2.0)
F = Intersect(c, c_3, 1.0)
c_4 = Circle(B, A)
C = Intersect(c, c_4, 1.0)
D = Mirror(C, OA)
AB = Segment(A, B)
BC = Segment(B, C)
CD = Segment(C, D)
DF = Segment(D, F)
FA = Segment(F, A)