O = (2.94, -0.42)
c = Circle(O, 4)
A = Point(c)
B = Point(c)
C = Point(c)
f = Segment(C, B)
g = Segment(C, A)
h = Segment(O, B)
i = Segment(O, A)
α = Angle(B, O, A)
β = Angle(B, C, A)