SAT Question 5b918ebb: Lines, Angles, and Triangles answer and explanation with Desmos solution

It's given that line $r$ is parallel to line $s$. Since line $n$ intersects both lines $r$ and $s$, it's a transversal. The angles in the figure marked as $162^{\circ }$ and $x^{\circ }$ are on the same side of the transversal, where one is an interior angle with line $s$ as a side, and the other is an exterior angle with line $r$ as a side. Thus, the marked angles are corresponding angles. When two parallel lines are intersected by a transversal, corresponding angles are congruent and, therefore, have equal measure. It follows that the value of $x$ is $162$.