E_1 = (-6.057978163022511, -11.480476279221453)
A = (-2.190151448964935, -4.948957582841206)
D = (11.712131362883529, -4.803001857782429)
a = Segment(A, D)
c = Semicircle(A, D)
B = Point(c)
b = Segment(A, B)
d = Segment(B, D)
C = Mirror(B, a)
e = Segment(A, C)
f = Segment(D, C)
α = Angle(D, A, B)
β = Angle(C, A, D)
γ = Angle(A, B, D)
δ = Angle(D, C, A)