$B$

$C$

$A$

$a$

$O$

$A'$

B = (1.7810833768440515, -0.056575151208458165)
C = (5.919807775447678, 0.3468384183305241)
A = (2.42355683944317, 2.6627311323506064)
poly1, c, a, b = Polygon(B, C, A)
d = Circle(B, C, A)
O = Center(d)
e = Ray(C, O)
A' = Intersect(d, e, 2)
poly2, e_1, a_1, b_1 = Polygon(B, C, A')
α = Angle(B, A, C)
α' = Angle(B, A', C)