O = Point(xAxis)
R = 0.9 (slider from 0 to 5, step 0.1)
α = 0 (slider from 0 to 360, step 5)
x_C: 2 * 3.14159 R α / 360
C: (x_C, R)
β = 45 (slider from 0 to 360, step 5)
c = Circle(C, R)
H = Intersect(c, xAxis, 1)
a = Segment(C, H)
A = Rotate(H, 3.14 * (β - α) / 180, C)
b = Segment(C, A)
γ = Angle(H, C, A)
OH = Distance(O, H)
T1: "L = " + OH