According to the given problem,
![\angle7=131^(\circ)](https://img.qammunity.org/2023/formulas/mathematics/college/b8xd03fws7e4ljda7oow58zcp9qsmc58ew.png)
Note: When two lines are intersecting, then the pair of vertivally opposite angles are always equal.
Since the angles 1 and 7 are vertically opposite angles formed due to the intersection of lines 'p' and 'r'. So they must also be equal,
![\begin{gathered} \angle1=\angle7 \\ \angle1=131^(\circ) \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/5zvv4s1ljdcxcp05hf5tlkl1cjy91peq6n.png)
Thus, the angle 1 measures 131 degrees.