Answer
$m \angle Z = 35^{\circ}$
Work Step by Step
In congruent polygons, vertices are named in the exact order of their matching vertices.
If $WXYZ$ is congruent to $PQRS$, then vertex $W$ corresponds to vertex $P$, vertex $X$ corresponds to vertex $Q$, vertex $Y$ corresponds to vertex $R$, and vertex $Z$ corresponds to vertex $S$.
Therefore, $\angle Z$ is congruent to $\angle S$. So, $m \angle Z$ is equal to $m \angle S$. If $m \angle S$ is $35^{\circ}$, then $m \angle Z$ is $35^{\circ}$.
