r = 1.7 (slider from 0.2 to 5, step 0.1)
O = (-3.422942148625557, 3.6898295213843606)
c = Circle(O, r)
A = Point(c)
B = Point(c)
C = Point(c)
a = Ray(C, A)
b = Ray(B, A)
d = Segment(B, C)
D = Point(a)
E = Point(b)
e = Segment(B, E)
f = Segment(C, D)
α = Angle(D, A, B)
β = Angle(B, A, C)
g = CircleArc(O, A, B)
h = CircleArc(O, C, A)
γ = Angle(C, B, A)
δ = Angle(A, C, B)