Puissance d'un point par rapport à un cercle
Author: Patrice Debart

O = (7, 0)
P = (8, -3)
c = Circle(O, P)
A = (0, 0)
B = Point(c)
dAO = Ray(A, O)
dAB = Ray(A, B)
C = Intersect(c, dAB, 2.0)
D = Intersect(c, dAO, 1.0)
E = Intersect(c, dAO, 2.0)
I = Midpoint(A, O)
c2 = Circle(I, O)
T = Intersect(c, c2, 2.0)
dAT = Ray(A, T)
OB = Segment(O, B)
BT = Segment(B, T)
CT = Segment(T, C)
OC = Segment(O, C)
OT = Segment(O, T)
r: Length[Vector[D, E]] / 2.0
d = Length(Vector[Vector[A, O]])
p: Length[Vector[A, B]] * Length[Vector[A, C]]
t = Length(Vector[Vector[A, T]])
p_2: d^(2.0) - r^(2.0)
p_1: t^(2.0)