standard_description: Recognize angle measure as additive. When an angle is decomposed into non-overlapping parts, the angle measure of the whole is the sum of the angle measures of the parts. Solve addition and subtraction problems to find unknown angles on a diagram in real world and mathematical problems, e.g., by using an equation with a symbol for the unknown angle measure.
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