Angles Q and R of a ΔPQR are 25° and 65°.
Write which of the following is true:
(i) PQ2 + QR2= RP2
(ii) PQ2 + RP2= QR2
(iii) RP2 + QR2= PQ2
The sum of the measures of all interior angles of a triangle is 180º.
∠PQR + ∠PRQ + ∠QPR = 180º
25º + 65º + ∠QPR = 180º
90º + ∠QPR = 180º
∠QPR = 180º − 90º = 90º
Therefore, Δ PQR is right-angled at point P.
Hence, (PR)2 + (PQ)2 = (QR)2
Thus, (ii) is true.