Question 136
Let $ABCD$ be a parallelogram. The points $P$ and $Q$ lie inside $ABCD$ on the diagonal $AC$, where $|AP| = |CQ| \lt \frac{1}{2}|AC|$ applies. The line $BP$ intersects $AD$ at the point $E$, the line $BQ$ intersects $CD$ at $F$. Show that $EF$ is parallel to the diagonal $AC$.