Figuur I

straal = 3 (slider from 0 to 5, step 0.1)
A = (-8, -15)
c = Circle(A, straal)
B = Point(c)
f = Line(B, A)
C = Intersect(c, f, 2)
e_1 = CircleArc(A, B, C)
g = Segment(B, A)
h = Segment(A, C)
D = Point(e_1)
i = Segment(C, D)
j = Segment(A, D)
α = Angle(A, D, C)
β = Angle(A, C, D)
γ = Angle(D, A, B)