A = (0.11887600204673587, 3.491949513900736)
B = (6.07675592699983, 3.590917618966397)
a = Segment(A, B)
D = (-1.1875029848200556, -1.0605833191199059)
b = Segment(A, D)
c = Line(D, a)
D_1 = Midpoint(a)
d = OrthogonalLine(D_1, a)
E = Intersect(c, d)
C = Mirror(D, d)
e = Segment(B, C)
đa giác1, a_1, b_1, c', c_1 = Polygon(A, B, C, D)
α = Angle(B, C, D)
β = Angle(C, D, A)
f = Segment(B, D)
g = Segment(A, C)