A = (10.120000000000001, -0.8)
B = (-0.9, -1.22)
a = Ray(A, B)
C = (2.24, 2.98)
b = Ray(A, C)
c = Segment(B, C)
B' = Point(a)
d = Line(B', c)
C' = Intersect(d, b)
α = Angle(A, B', C')
β = Angle(A, B, C)
γ = Angle(B, C, A)
δ = Angle(B', C', A)
texte1: "k = AB’/AB =" + (Distance[A, B'] / Distance[A, B])