We have,
QTPR=QRQS [Given]
⇒ QTQR=PRQS.......(i)
We also have,
∠1=∠2 [Given]
⇒PR=PQ [Sides opposite to equal angles are equal].....(ii)
From (i) and (ii), we get
QTQR=PQQS
⇒ PQQT=QSQR
Thus, in triangles PQS and TQR, we have
PQQT=QSQR and ∠PQS=∠TQR=∠Q
So, by SAS-criterion of similarity, we have
△PQS∼△TQR. [Hence proved]