Choose correct alternative answer and fill in the blank.
Length of a chord of a circle is 24 cm. If distance of the chord from the centre is 5 cm, then the radius of that circle is ....
Let the chord be AB = 24 cm
Distance of the chord from the centre O is 5 cm.
AO is the radius of the circle.
Perpendicular from the centre of the circle to the chord bisects the chord.
So, AC = CB
In Δ AOC,
OC2 + AC2 = AO2
⇒ 52 + 122 = AO2
⇒ AO2 = 25 + 144 = 169
⇒ AO = 13 cm
Thus, the radius of the circle is 13 cm.