E_1 = (-6.057978163022511, -11.480476279221453)
B = (-2.190151448964935, -5.6057583456057)
C = (13.31764433853007, -5.642247276870394)
a = Segment(B, C)
c = Semicircle(B, C)
A = Point(c)
b = OrthogonalLine(A, a)
H = Intersect(b, a)
d = Segment(B, A)
e = Segment(A, C)
f = Segment(A, H)
α = Angle(C, H, A)
β = Angle(B, A, C)