D = (0.7720654954801314, -1.3970748763431704)
C = (6.45283472624936, -1.337694013303771)
a = Segment(D, C)
C_1 = (-2.57305645573938, 2.898140883506735)
m = Line(C_1, a)
c = LineBisector(a)
A = Point(m)
B = Mirror(A, c)
d = Segment(A, C)
e = Segment(B, D)
đa giác1, d_1, a_1, b, c_1 = Polygon(D, A, B, C)
α = Angle(C, D, A)
β = Angle(B, C, D)