r = 2 (slider from 1 to 3, step 1)
A = Intersect(zAxis, xAxis)
B = Point(yAxis)
a, c, d, b = Cylinder(A, B, r)
r1 = 3 (slider from 3 to 7, step 1)
C = Intersect(zAxis, xAxis)
e, f, g, h = Cylinder(C, B, r1)
D = PointIn(h)