O = (3.333554768198537, 2.9863638162682746)
c = Circle(O, 4)
C = Point(c)
B = Point(c)
A = Point(c)
D = Point(c)
hulknurk1, a, b, c_1, d = Polygon(A, B, C, D)
α = Angle(C, B, A)
β = Angle(D, C, B)
γ = Angle(A, D, C)
δ = Angle(B, A, D)