In trianglePQR, if AB//QR, PA=3cm, PQ=8cm, and QR=9cm, how long is AB?
The two triangles formed (PAB and PQR) are similar.
Ratio of sides = PA/PQ
= 3/8
The ratio remains constant for all pairs of sides, in similar triangles.
=> AB/QR = 3/8
=> AB = (3/8)*QR
=> AB = (3/8)*9
= 27/8 cm