M = (-1.9712280150640495, 2.395464212671222)
c = Circle(M, 2.0)
H = Point(c)
a = Segment(H, M)
b = OrthogonalLine(H, a)
H' = Rotate(H, 55.0*°, M)
α = Angle(H, M, H')
d = Line(M, H')
A = Intersect(d, b)
C = Mirror(A, M)
b' = Mirror(b, d)
e = LineBisector(A, C)
D = Intersect(e, b)
B = Intersect(b', e)
Vieleck1, e_1, c', d_1, c_1 = Polygon(B, C, D, A)
β = Angle(B, A, D)