Question 39
Let $ABCD$ be a rectangle of center $O$, such that $\widehat{DAC}=60^{\circ}$. The angle bisector of $\widehat{DAC}$ meets $DC$ at $S$. Lines $OS$ and $AD$ meet at $L$ and lines $BL$ and $AC$ meet at $M$. Prove that lines $SM$ and $CL$ are parallel.