S_1 = (7.975217860764686, 1.8747007474383612)
A_{1} = (4.92, -0.84)
k_1 = Circle(S_1, A_{1})
a = 0 (slider from 0 to 5, step 1)
A_{2} = (1.7401133463713283, -3.7728022943943498)
B = (14.699990268958567, -2.662888401779828)
p = Line(A_{2}, B)
A = Point(p)
f = OrthogonalLine(A, p)
g = Line(S_1, A)
C = Intersect(k_1, g, 2)
D = Midpoint(C, A)
c = Hyperbola(A, S_1, D)
S_2 = Intersect(c, f, 2)
k_2 = Circle(S_2, A)
S_3 = Intersect(c, f, 1)
d = Circle(S_3, A)