E_1 = (-6.057978163022511, -11.480476279221453)
O = (6.165813810650021, -2.3582434630479225)
I = (21.63712066688033, -2.467710256842005)
a = Segment(O, I)
c = Semicircle(O, I)
M = Point(c)
N = Mirror(M, a)
b = Segment(O, M)
d = Segment(M, I)
e = Segment(I, N)
f = Segment(N, O)
α = Angle(O, M, I)
β = Angle(I, N, O)
γ = Angle(I, O, M)
δ = Angle(N, O, I)