MathDB
Tangent Circles

Source: AIME 2008II Problem 11

April 3, 2008
trigonometryquadraticsgeometryprobabilityAMCAIMEtrapezoid

Problem Statement

In triangle ABC ABC, AB \equal{} AC \equal{} 100, and BC \equal{} 56. Circle P P has radius 16 16 and is tangent to AC \overline{AC} and BC \overline{BC}. Circle Q Q is externally tangent to P P and is tangent to AB \overline{AB} and BC \overline{BC}. No point of circle Q Q lies outside of ABC \triangle ABC. The radius of circle Q Q can be expressed in the form m \minus{} n\sqrt {k}, where m m, n n, and k k are positive integers and k k is the product of distinct primes. Find m \plus{} nk.