1. **State the problem:** Identify which pairs of angles are vertical angles. 2. **Definition:** Vertical angles are the pairs of opposite angles made by two intersecting lines. They are always equal. 3. **Analyze the given pairs:** - ∠2 and ∠4: These are opposite angles formed by the intersection, so they are vertical angles. - ∠2 and ∠5: These are not opposite angles; ∠5 is adjacent to ∠2, so not vertical. - ∠2 and ∠1: These are adjacent angles sharing a common side, so not vertical. - ∠5 and ∠4: These are opposite angles formed by the intersection, so they are vertical angles. 4. **Conclusion:** The vertical angle pairs are ∠2 and ∠4, and ∠5 and ∠4. **Final answer:** - ∠2 and ∠4 - ∠5 and ∠4