Given:
Q is a point on side SR in ΔPSR such that PQ=PR
⇒PS>PR …… (1)
Proof:
In ΔPQR,
PQ=PR
⇒∠PQR=∠PRQ
Now, from (1)
∠PRQ>∠PSQ or ∠PRS>∠PSR
Now, in ΔPSR,
∠PRS>∠PSR
⇒PS>PR
⇒PS>PQ
Hence, proved.
In a triangle PQR right angled at Q if QS = SR then prove that PR2 = 4PS2 - PQ2