Answer:
III. Angle 2 and Angle 6.
Explanation:
Given that the two lines r and s are cut by a transversal such that angles 2 and 6 are congruent.
This congruency implies that angles 2 and 6 are corresponding angles formed by the transversals.
However, this can only occur if the two lines are parallel.
Therefore, the pair of congruent angles that can help prove that the lines are parallel is angle 2 and angle 6.
