Question

In the given figure, AB||CD and if $\angle CFE={90}^{\circ }$, then $\angle FEB=$ __${}^{\circ }$.

Answer 1

As stated in question AB||CD and if $\angle CFE$ = ${90}^{\circ }$, so $\angle FEB$ is an alternate angle to $\angle CFE$ which should be equal.
So, $\angle FEB={90}^{\circ }$.