Two Circumcircles
Source: AIME II 2010 Problem #15
April 1, 2010
geometrycircumcircleratiogeometric transformationSpiral Similarityangle bisectorAIME
Problem Statement
In triangle , AC \equal{} 13, BC \equal{} 14, and AB\equal{}15. Points and lie on with AM\equal{}MC and \angle ABD \equal{} \angle DBC. Points and lie on with AN\equal{}NB and \angle ACE \equal{} \angle ECB. Let be the point, other than , of intersection of the circumcircles of and . Ray meets at . The ratio can be written in the form , where and are relatively prime positive integers. Find m\minus{}n.