Inscribed Angle Theorem
Author: Hans-Peter Schröcker
Date: July 21, 2010

A = (1.76, 1.04)
c = Circle(A, 5.0)
B = Point(c)
C = Point(c)
D = Point(c)
a = Segment(D, B)
b = Segment(B, C)
d = Segment(C, D)
α = Angle(B, D, C)