PL-OM 2001 Problem 5

Let $ABCD$ be a parallelogram and let $K$ and $L$ be points on the segments $BC$ and $CD$ , respectively, such that $BK\cdot AD=DL\cdot AB$ . Let the lines $DK$ and $BL$ intersect at $P$ . Show that $\measuredangle DAP=\measuredangle BAC$ .