Problem

Source: Brazil EGMO TST 2021 #7

Tags: geometry



The incircle $\omega$ of a triangle $ABC$ touches the sides $BC, AC, AB$ in the points $D, E, F$ respectively. Two different points $K$ and $L$ are chosen in $\omega$ such that $\angle CKE+\angle BKF=\angle CLE+\angle BLF=180^{\circ}$. Prove that the line $KL$ is in the same distance to the point $D, E,$ and $F$.