A = (13.85733587627406, 3.773261482834591)
B = (10.57711442810645, -3.453091030797819)
C = (18.71600975062759, -3.379101073320354)
a = Line(A, B)
d = Line(B, C)
c = Line(C, A)
d_1 = Segment(A, B)
e = OrthogonalLine(A, d)
H = Intersect(d, e)
f = Segment(A, H)
b = Segment(A, C)
D = (10.13317468324166, -5.845432989235853)
E = (12.451526684202227, -5.9687495850316274)
g = Segment(D, E)
h = Circle(H, g)
F = Intersect(h, d, 2.0)
α = Angle(F, H, A)