standard_description: Prove theorems about lines and angles. Theorems include: vertical angles are congruent; when a transversal crosses parallel lines, alternate interior angles are congruent and corresponding angles are congruent; points on a perpendicular bisector of a line segment are exactly those equidistant from the segment’s endpoints.
problem_activity: Task
In the picture below, lines $l$ and $m$ are parallel. The measure of angle $\angle PAX$ is $31^\circ$, and the measure of angle $\angle PBY$ is $54^\circ$. What is the measure of angle $\angle APB$?
[IMG]


aligns: no