In below shown figure, PSSQ=PTTR and∠PST=∠PRQ. Then ΔPQR is an
It is given that
PSSQ=PTTR
So, ST||QR
∴, ∠PST=∠PQR (Corresponding Angles)
Also, it is given that
∠PST=∠PRQ
So,∠PRQ=∠PQR
Therefore, PQ = PR (Sides opposite the equal angles)
i.e., ΔPQR is an isosceles triangle.