Mesure de l'angle

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B = (0.5462931656783461, 0.3859040635805781)
A = (8.133302642308665, 0.9633929738752723)
a = Ray(B, A)
α = 0.47123889803846897 rad (slider from 0 to 3.141592653589793, step 0.017453292519943295)
A' = Rotate(B, α, B)
C = Rotate(A, α, B)
a' = Ray(A', C)
β = Angle(A, B, C)
O = Midpoint(B, C)
b = Ray(C, B)
C' = Rotate(C, -α, C)
D = Rotate(B, -α, C)
b' = Ray(C', D)
γ = Angle(D, C', B)
c = OrthogonalLine(O, a)
E = Intersect(c, a)
F = Intersect(b', c)
δ = Angle(A, E, O)
d = false
G = Point(b')
H = Point(c)
I = Midpoint(H, G)
ε = Angle(H, F, G)