1. **State the problem:** Given that $m\angle SQT = 30^\circ$ and $m\angle P = 85^\circ$, and that $\angle SQT$ and $\angle PQR$ are vertical angles, find $m\angle R$.
2. **Use the Vertical Angle Theorem:** Vertical angles are congruent, so
$$m\angle SQT = m\angle PQR$$
which means
$$m\angle PQR = 30^\circ$$
3. **Apply the Triangle Sum Theorem:** The sum of the interior angles of triangle $PQR$ is
$$m\angle PQR + m\angle P + m\angle R = 180^\circ$$
Substitute the known values:
$$30^\circ + 85^\circ + m\angle R = 180^\circ$$
4. **Simplify the equation:**
$$115^\circ + m\angle R = 180^\circ$$
5. **Solve for $m\angle R$:**
$$m\angle R = 180^\circ - 115^\circ$$
$$m\angle R = 65^\circ$$
**Final answer:**
$$\boxed{65^\circ}$$
Angles Parallel Lines Fde749
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