Question

Two chords AB and CD intersect at point O inside the circle. If OA = 5 cm, OB = 6 cm and OC = 3 cm, then find the length of CD.

Answer 1

When two chords intersect each other in a circle, the product of the chord segments will be equal.
So, $OA\times OB=OD\times OC$ ( 0.5 mark)
$5\times 6=OD\times 3$
$OD=10cm$ (0.5 mark)
$CD=OC+OD=3+10=13cm$ ( 1 mark)