A = (6, -1)
B = (12, -1)
c = Circle(A, B)
α = 2.4923301718479025 rad (slider from 0 to 6.283185307179586, step 0.05°)
M = Rotate(B, α, A)
β = Angle(B, A, M)
d = Circle(A, M, B)
f = Segment(A, M)
g = Segment(M, B)
h = OrthogonalLine(B, f)
i = OrthogonalLine(A, g)
C = Intersect(h, i)