Question 86
Let $ABCDE$ be a convex pentagon such that $\angle ABE=\angle ACE=\angle ADE=90^\circ$ and $BC=CD$. Let $K$ be a point on ray $AB$ with $AK=AD$, and let $L$ be a point on ray $ED$ with $EL=BE$. Prove that $B,D,K,L$ lie on one circle with center $C$.