Answer:
We are given that triangle PQR is an isosceles triangle in which PQ = PR .
Since the base angles of an isosceles triangle are equal,
angle PQR = angle PRQ
Also, And we are given that
angle MRQ = angle NQR
In ΔQNR and ΔRMQ
∠NQR=∠MRQ (given)
QR = QR (common)
-triangles QNR is congruent to triangles RMQ - ASA - angle side angle