B2 = 0.08
B1 = -0.13
T = 240 (slider from 20 to 500, step 20)
A = Point(yAxis)
DL: -1.0 * (T - 20.0) / 480.0 * (B2 - B1) + B2
B: (DL, 0.0)
a = Ray(A, B)
C = Point(yAxis)
c = Circle(C, 1.0)
D = Intersect(c, a, 1.0)
D' = Rotate(D, 240.00000000000003°, C)
α = Angle(D, C, D')
b = Ray(C, D')
β = Angle(b, xAxis)
γ: β - 180.0 * °
F = Point(b)
u = Vector(C, F)
G = Point(a)
e = Segment(A, G)
H = Point(xAxis)
f = Segment(H, B)
E: (x(B) * 100.0, γ / 10.0 / °)