n triangles ABC and PQR, ∠A = ∠Q and ∠B = ∠R. Which side of ∆ PQRshould be equal to side AB of ∆ ABC so that the two triangles are congruent?Give reason for your answer.

In order for triangles ABC and PQR to be congruent, side PQ of triangle PQR should be equal to side AB of triangle ABC. This is based on the Angle-Angle-Side (AAS) congruence rule, which states that if two angles and the non-included side of one triangle are equal to two angles and the non-included side of another triangle, then the triangles are congruent. Here, ∠A = ∠Q and ∠B = ∠R are the two pairs of equal angles, and side AB of triangle ABC should be equal to side PQ of triangle PQR for the triangles to be congruent.