To determine which angle is a vertical angle to ∠5, we need to know the relationships between angles formed by two intersecting lines. Vertical angles are the pairs of angles that are opposite each other when two lines cross.
If you know the position of ∠5 in relation to other angles, you can determine its vertical angle. For example, if ∠5 is adjacent to two angles (let's say ∠4 and ∠6), then the vertical angle to ∠5 would be the angle opposite to it (e.g. ∠3).
Since the context or diagram is not provided here, I cannot specify which angle is vertical to ∠5. If you have a specific arrangement or diagram involving ∠5, please describe it or share the diagram, and I can assist you in identifying the vertical angle.