# 3 centers collinear

Let $D$ be point lie on $BC$ of $\Delta ABC$. Let $I$ and $J$ be incenters of $\Delta ABD$ and $ACD$. Let $P, Q, R$ be circumcenters of $\Delta AIJ, \Delta BIJ, \Delta CIJ$.

Prove that $P, Q, R$ are collinear.

Author: Van Khea, Cambodia