a = 0 (slider from 0 to 7, step 1)
S_1 = (4.1, -3.84)
S_2 = (6.6, -2.76)
f = Line(S_1, S_2)
C = Point(f)
k_1 = Circle(S_1, C)
k_2 = Circle(S_2, C)
S_3 = (11.5, 4.88)
E = (10.334, 2.694)
k_3 = Circle(S_3, E)
g = OrthogonalLine(C, f)
h, i = Tangent(g, k_3)
F = Intersect(k_3, h, 1)
G = Intersect(k_3, i, 1)
j = Line(G, C)
k = Line(F, C)
H = Intersect(k_3, j, 2)
I = Intersect(k_3, k, 2)
l = LineBisector(H, C)
m = LineBisector(I, C)
S_{4} = Intersect(f, l)
S_{5} = Intersect(f, m)
k_{5} = Circle(S_{5}, C)
k_4 = Circle(S_{4}, C)