33. In the following diagram, $A B C D$ is a square, $B D \| C E$ and $B E=B D$. Let $\angle E=x^{\circ}$. Find $x$.
33. Answer: 30.
Draw $B F \perp C E$, where $F$ is on $C E$. If $A B=1$, then $B F=\frac{\sqrt{2}}{2}$ and $B E=\sqrt{2}$. Thus $\angle E=30^{\circ}$.