A = (5, -15)
B = (10, -5)
C = (20, -15)
D = (25, -5)
a = Segment(A, C)
b = Segment(C, D)
c = Segment(D, B)
d = Segment(B, A)
α = Angle(C, A, B)
E = (25, -15)
e = Segment(E, C)
β = Angle(E, C, D)
F = (10, -15)
f = Segment(B, F)
G = (25, -15)
g = Segment(D, G)