MathDB
2017-2018 Spring OMO Problem 14

Source:

April 3, 2018

Problem Statement

Let ABCABC be a triangle with AB=20AB=20 and AC=18AC=18. EE is on segment ACAC and FF is on segment ABAB such that AE=AF=8AE=AF=8. Let BEBE and CFCF intersect at GG. Given that AEGFAEGF is cyclic, then BC=mnBC=m\sqrt{n} for positive integers mm and nn such that nn is not divisible by the square of any prime. Compute 100m+n100m+n.
Proposed by James Lin