To solve this problem, we need to apply the properties of angles formed when parallel lines are cut by a transversal.
Given that \( PQ \parallel RS \) and \( m\angle PVT = 109^\circ \), we can analyze the relationships between the angles:
- \( m\angle PVT \) (which is given as \( 109^\circ \)) is an exterior angle at the intersection with a transversal.
- When parallel lines are cut by a transversal, the corresponding angles are equal, and the alternate interior angles are also equal.
Using these properties, angle \( RWU \) would be the angle that is in a corresponding or alternate position relative to angle \( PVT \):
- Since \( m\angle PVT + m\angle RWU = 180^\circ \) (because they are consecutive interior angles), we can determine \( m\angle RWU \) as follows:
\[ m\angle RWU = 180^\circ - m\angle PVT = 180^\circ - 109^\circ = 71^\circ \]
Therefore, the measure of angle \( RWU \) is \( 71^\circ \).
The answer is 71°.