S = (17.58, -6.06)
B_{1} = (13.34, -0.86)
k = Circle(S, B_{1})
A = Point(k)
B = (17.18, -14.9)
f = Line(A, S)
g = Line(A, B)
B' = Intersect(k, g, 2)
h = Line(B', S)
i = Line(B, h)
S_1 = Intersect(f, i)
k_1 = Circle(S_1, A)
a = 0 (slider from 0 to 5, step 1)