Chapter 12, Problem 2STP

To determine

To calculate : The radius of the cicle.

Answer to Problem 2STP

The radius of the circle would be $7mm$

Explanation of Solution

Given information : The diagram is given. Where $\overline{HK}$ is the tangent to the circle $O$ .

  

Formula used : The tangent of the circle makes $90°$ angle with the radius. So, we get a right-angled triangle $OKH$ . So, using the Pythagorean theorem $O{K}^2=O{H}^2-K{H}^2$

Calculation : Calculate the radius.

  $O{K}^2=O{H}^2-K{H}^2$

  $\begin{array}{l}{r}^2={25}^2-{24}^2\\ r^2=625-576\\ r^2=49\\ \sqrt{r^2}=\sqrt{49}\\ r=7mm\end{array}$