Question

look at this diagram: if $overleftrightarrow{su}$ and $overleftrightarrow{vx}$ are parallel lines and $mangle utr = 137^{circ}$, what is $mangle str$?

Explanation:

Step1: Recall angle - addition property

$\angle UTR+\angle STR = 180^{\circ}$ (linear - pair of angles).

Step2: Solve for $\angle STR$

$\angle STR=180^{\circ}-\angle UTR$.
Since $\angle UTR = 137^{\circ}$, then $\angle STR=180 - 137=43^{\circ}$.

Answer:

$43$