If ΔPQR and ΔXYZ are congruent under the correspondence QPR ↔ XYZ, then
(i) ∠R = ∠Z
(ii) QR = XZ
(iii) ∠P = ∠Y
(iv) QP = XY
(v) ∠Q = ∠X
(vi) RP = ZY
From correspondence QPR ↔ XYZ, match vertices: Q→X, P→Y, R→Z. Hence respective angles and sides are equal.