A = (-4.164159278012201, 2.7124288781567394)
B = (6.244020945694592, 9.520787370355919)
a = Segment(A, B)
c = Semicircle(B, A)
O = Point(c)
D = Mirror(B, O)
C = Mirror(A, O)
đa giác1, a_1, b, a', b' = Polygon(A, B, C, D)
d = Segment(B, D)
e = Segment(C, A)