In a ΔPQR, PQ = 10 cm, QR = 12 cm and semi perimeter is 17 cm. What is the length of PR ?

15 cm  7 cm 12 cm  10 cm

12 cm

Semi perimeter = 17 cm PQ = 10 cm QR = 12 cm Semi perimeter = \(\frac{PQ + QR + RP}{2}\)  17 = \(\frac{10 + 12 + RP}{2}\)  RP = 12 cm