Question

The radius of a circle is 8 cm and the length of one of its chords is 12 cm. Find the distance of the chord from the centre.

Answer 1

Radius = OA = 8 cm
AB = 12 cm



Draw a perpendicular OC on AB.

We know that perpendicular from centre to chord bisects the chord

Thus, AC = BC = 6 cm

In $\Delta$OCA, using Pythagoras theorem,

$O{A}^2=A{C}^2+O{C}^2$

$64=36+O{C}^2$

$O{C}^2=64–36=28$

$OC=\sqrt{28}=5.291$ cm