C = (8.690184419052954, 3.4103248523432703)
A = (0.09869969400224501, -2.295217127227085)
B = (4.344684422984835, -2.5937629284836734)
đa giác1, c, a, b = Polygon(C, A, B)
D = Mirror(C, a)
đa giác2, c_1, b_1, a' = Polygon(A, D, B)
α = Angle(A, C, B)