r = 1.7 (slider from 0.2 to 5, step 0.1)
O_1 = (-2.828712847414411, 4.178727207330659)
O = (-2.3994368304859592, 4.1171181493455515)
c = Circle(O, r)
A = (-4.903546929235266, 5.9455159992259965)
B = Point(c)
a = Segment(A, B)
D = Intersect(c, a, 2)
b, d = Tangent(A, c)
C = Intersect(c, d, 1)
e = Ray(A, C)
E = Point(e)
f = Segment(A, E)
α = Angle(B, A, C)
g = Segment(C, B)
β = Angle(B, C, E)
γ = Angle(C, B, D)
h = CircleArc(O, C, D)
k = CircleArc(O, B, C)