A = (10, 10)
B = (-20, 10)
C = (-20, 30)
D = (10, 30)
E = (50, 30)
F = (50, 10)
G = (10, -10)
a = Line(C, E)
b = Ray(A, B)
H = (30, 10)
c = Ray(H, F)
d = Ray(A, G)
I = (30, -10)
e = Ray(H, I)
J = Point(a)
f = Ray(J, A)
K = Intersect(e, f)
g = Segment(J, K)
α = Angle(G, A, K)