Question

In the given figure, chords AB and CD when extended meet at P. If AB = 4 cm, BP = 6 cm, DP = 5 cm, then find the value of CD.

Answer 1

If two chords intersect externally, then $PA\times PB=PC\times PD$

$10\times 6=PC\times 5$ ........ (PA = AB + BP)

PC = 12 cm

CD + DP = 12 cm

CD = 12 – 5 ......... (DP = 5cm)

CD =7 cm