Question

The chord of length $30cm$ is drawn at the distance of $8cm$ from the centre of the circle. Find the radius of the circle

Answer 1

Distance $AC=\frac{1}{2}\times$ Length of chord
$\begin{array}{cc}& =\frac{1}{2}\times 30\\ & =15cm\end{array}$
Distance from the centre $=8cm$
$\begin{array}{cc}& \text{In}△OAC\text{Radius}\left(OA\right)=\sqrt{{AC}^2+{OC}^2}\\ & =\sqrt{{15}^2+8^2}\\ & =\sqrt{225+64}\\ & =\sqrt{289}\\ & =17\end{array}$
Radius of the circle $=17cm$.