O = Intersect(xAxis, yAxis)
c = Circle(O, 1)
A = Point(c)
B = (1, 0)
a = Segment(O, A)
b = Segment(O, B)
β = Angle(B, O, A)
d = Line(A, xAxis)
f = Line(A, yAxis)
C = Intersect(d, yAxis)
D = Intersect(f, xAxis)
e = Segment(C, A)
g = Segment(D, A)
E = Point(c)
h = Segment(E, O)
α = Angle(A, O, E)