MN || QR => MNP asemenea cu RQP
a) NP/PQ = MN/RQ => 3/6 = 2/QR => QR = 6 × 2 /3 = 4 cm
b) PM/PR = MN/QR => 2/3 = MN/8 => MN = 2 × 8 / 3 = 5.33 cm
