Apollonius' Problem -- from Wolfram MathWorld
2. You can reduce a circle around to a point if you use the radius 0:
will yield M.
Given two circles of different radii, and a point, find the circle which will be tangent to all three of these. A circle is tangent to a point if the point is on the solution circle. If you can reduce one of the circles to a point or line that would be great because I have the scripts for every other solution except this one >_<.