Question

which pair of angles are vertical angles?
∠mrc and ∠krm
∠kre and ∠ert
∠krc and ∠crh
∠ert and ∠mrc

Explanation:

Vertical angles are pairs of non-adjacent angles formed when two lines intersect, and they are congruent. We analyze each option:

1. $\angle MRC$ and $\angle KRM$: These share a common side and are adjacent, not vertical.
2. $\angle KRE$ and $\angle ERT$: These share a common side and are adjacent, not vertical.
3. $\angle KRC$ and $\angle CRH$: These are adjacent and form a straight line (linear pair), not vertical.
4. $\angle ERT$ and $\angle MRC$: These are formed by the intersection of lines $MT$ and $EC$, are non-adjacent, and match the definition of vertical angles.

Answer:

D. $\angle ERT$ and $\angle MRC$