A_1'

Určete, kolik společných tečen mohou mít kružnice k_1 a k_2. 
Měňte velikost poloměrů a vzájemnou polohu středů kružnic.

r_1 = 2.5 (slider from 0 to 5, step 0.05)
r_2 = 1 (slider from 0 to 5, step 0.05)
S_1 = Point(xAxis)
S_2 = Point(xAxis)
c = Circle(S_1, r_1)
d = Circle(S_2, r_2)
a = Line(S_1, S_2)
b = OrthogonalLine(S_1, a)
A, B = Intersect(c, b)
e = Line(B, a)
f = Line(A, a)
C = Point(d)
g = Segment(S_2, C)
h = Line(S_1, g)
D, E = Intersect(c, h)
i = Line(C, E)
j = Line(C, D)
F = Intersect(a, i)
G = Intersect(j, a)
k, l = Tangent(F, d)
m, n = Tangent(G, d)
p, q = Tangent(G, c)
b_1, c_1 = Tangent(F, c)
H, I = Intersect(c, a)
J, K = Intersect(d, a)
r = OrthogonalLine(I, a)
s = OrthogonalLine(H, a)
t = Segment(J, I)
a_1 = Segment(K, I)
d_1 = Segment(K, H)
e_1 = Segment(J, H)