A = (1.508836912418215, 3.539312718912282)
B = (-2.8517303025562506, 0.10516637744887469)
C = (-0.05649490834184606, 0.08919360376764951)
đa giác2, c, a, b = Polygon(A, B, C)
h = Line(B, C)
j = OrthogonalLine(A, h)
H = Intersect(j, h)
h_a = Segment(A, H)
A_1 = (-1.9093366553639675, -2.7220145641279774)
B_1 = (-0.695405855590856, -2.7060417904467524)
a_1 = Segment(A_1, B_1)
c_1 = Circle(H, a_1)
C_1 = Intersect(c_1, h_a, 1.0)
G = Intersect(c_1, h, 1.0)
α = Angle(C_1, H, G)