P(cos(α),sin(α))

(0,sin(α))

(cos(α),0)

P = Point(c)
a = OrthogonalLine(P, xAxis)
b = OrthogonalLine(P, yAxis)
B = Intersect(b, yAxis)
C = Intersect(a, xAxis)
d = Segment(B, P)
e = Segment(P, C)
A = Intersect(xAxis, yAxis)
f = Segment(P, A)
D = (1, 0)
α = Angle(D, A, P)