Question

The radius of a circle is 15 cm and the length of one of its chord is 18 cm. Find the distance of the chord from the centre.

Answer 1

Let AB be the chord with length $=18cm$

$OA=radius=15cm$

Now, $OC\perp AB$

Then, $AC=CB=9cm$ (perpendicular drawn from the centre of the circle to the chord ,bisects the chord)

$\therefore OC=\sqrt{(O{A}^2-A{C}^2)}=\sqrt{({15}^2-9^2)}=\sqrt{\left(144\right)}=12cm$

Hence, $OC=12cm$