thales3collpoints

a = Segment(A, B)
D = Midpoint(A, B)
c = Circle(D, B)
b = OrthogonalLine(D, a)
E = Intersect(c, b, 1)
d = Ray(E, C)
F = Intersect(c, d, 2)
e = Segment(A, F)
f = Segment(B, F)
g = OrthogonalLine(F, a)