Quandaries
and Queries 

Name: Mitja Who is asking: Student Question: 

Hi Mitja, If you know about inversions, then the problem is easy: invert the given circles into a pair of concentric circles. Without inversion, one needs to know many facts about Euclidean constructions  more than is generally taught in high school. A complete solution is given in many college geometry books under the heading "the problem of Apollonius." Chris 

