Given, ΔABC and ΔPQR are congruent with,
∠B=∠Q=90∘
∠C=∠R
For ΔABC and ΔPQR to be congruent, the side in between the equal angles needs to be equal.
¯¯¯¯¯¯¯¯BC=¯¯¯¯¯¯¯¯¯QR
⇒ΔABC and ΔPQR are congruent by ASA congruence rule.
Then one additional pair is BC = QR.