Entry-Level Assessment - Page xxxvi: 5

$D$

Since $m$ and $n$ are parallel, we have that the angle with measure $132^{\circ}$ is congruent to the angle with measure $(x – 12)^{\circ}$ because they are alternate exterior angles. Therefore: $x – 12 = 132$ To solve for $x$, we just add $12$ on both sides: \begin{align*} x-12+12 &= 132+12\\ x&=144\end{align*}