S = (0, 0)
t = 0.15 (slider from 0 to 6.28318531, step 0.01)
R = 10
r = 1
E: R * (cos(t), sin(t))
c = Circle(E, r)
a = Segment(S, E)
b = OrthogonalLine(E, a)
A = Intersect(c, b, 2)
B = Intersect(c, b, 1)
d_1 = Segment(A, B)
C = Intersect(c, a, 1)
e = CircumcircleSector(A, C, B)
f = CircleSector(E, B, A)
g = Circle(S, r)
d = 3
L: E + r * (cos(d * t), sin(d * t))