PQR is an isosceles triangle in which PQ = PR Mand N are points on PQ and PR such that angle MRQ = angle NQR.

Prove that triangles QNR and RMQ are congruent.

Answer and Step-by-step explanation: Congruent triangles are triangles with the same three sides and same three angles.

There many ways to determine if 2 triangles are congruent.

One of them is ASA or Angle, Side, Angle and it means that if two angles and the included side of one triangle are equal to the corresponding angles and side on the other triangle, they are congruent.

In this case, angle MRQ and angle NQR are equal. The included side of both triangles are the same QR, so it can be concluded that triangle QNR is congruent to triangle RMQ.

The image in the attachment shows the angles and their included side, which are colored.