α

r

r sin α

r cos α

α = 0.9599310885968813 rad (slider from 0 to 6.283185307179586, step 0.017453292519943295)
M = (2, 1)
a = OrthogonalLine(M, yAxis)
A = Point(a)
P: (x(M) + (x(A) - x(M)) * cos(α), y(M) + (x(A) - x(M)) * sin(α))
r = Vector(M, A)
β = Angle(A, M, P)
b = Segment(M, P)
c = OrthogonalLine(P, r)
B = Intersect(c, a)
d = Segment(P, B)
e = Segment(M, B)