MathDB
Accuracy P10

Source:

October 16, 2021
MOAA 2021Accuracy

Problem Statement

In ABC\triangle ABC, let XX and YY be points on segment BCBC such that AX=XB=20AX=XB=20 and AY=YC=21AY=YC=21. Let JJ be the AA-excenter of triangle AXY\triangle AXY. Given that JJ lies on the circumcircle of ABC\triangle ABC, the length of BCBC can be expressed as mn\frac{m}{n} for relatively prime positive integers mm and nn. Compute m+nm+n.
Proposed by Andrew Wen