Question

A chord of length 40 cm is at a distance of 15 cm from the centre of circle find the radius of circle

Answer 1

Let chord = AB =15
Distance from centre =BC =40
we know that radius is perpendicular to the chord

By using Pythagoras theorem
$ac = \sqrt{ {40}^{2} - {15}^{2} } \ \\ ac = \sqrt{1600 - 225} \\ ac = \sqrt{1375} \\ ac = 37.08$
ac is the radius.

Your question is wrong because chord is never greater than it distance from centre