Answer:
The measure of ∠OPQ is 110°.
Explanation:
Draw a line parallel to OP from point Q. Label a point on the line T. (See attached diagram).
Angles SRQ and TQR are alternate interior angles, and so according to the Alternate Interior Angles Theorem, they are congruent.
⇒ m∠TQR = m∠SRQ = 130°
Given m∠PQR = 60° and m∠TQR = 130° then:
⇒ m∠TQP + m∠PQR = m∠TQR
⇒ m∠TQP + 60° = 130°
⇒ m∠TQP = 70°
Angles OPQ and TQP are same-side interior angles, and so according to the Same-side Interior Angles Theorem, they are supplementary (sum to 180°).
⇒ m∠OPQ + m∠TQP = 180°
⇒ m∠OPQ + 70° = 180°
⇒ m∠OPQ = 110°
Therefore, the measure of ∠OPQ is 110°.