A_1 = (3.94, -3.58)
O = (1.56, 0.52)
c = Circle(O, A_1)
B = Point(c)
A = Point(c)
a = Segment(A, O)
b = Segment(O, B)
β = Angle(A, O, B)
f = CircleArc(O, B, A)
S = Point(f)
d = Segment(A, S)
e = Segment(S, B)
α = Angle(A, S, B)