t = 0.65 (slider from 0 to 6.283185307179586, step 0.01)
a: x = t
M = Intersect(a, b)
c = Circle(M, 1.0)
O = Intersect(xAxis, yAxis)
C = Point(xAxis)
d = Line(O, C)
D = Intersect(a, d)
P = Rotate(D, -(t), M)
α = Angle(P, M, D)
e = Segment(M, P)
f = CircleArc(M, P, D)
g = Segment(O, D)