r_1 = 4 (slider from 0 to 5, step 0.1)
r_2 = 1 (slider from 0 to 2, step 0.1)
M_1 = Intersect(xAxis, yAxis)
c = Circle(M_1, r_1)
M_2 = Point(xAxis)
d = Circle(M_2, r_2)
e = Circle(M_1, r_1 + r_2)
P = Point(e)
a = Segment(M_2, P)
b = Segment(M_1, P)
f = LineBisector(M_2, P)
Q = Intersect(f, b)
g = Segment(Q, M_2)