Question

Find the length of the tangent drawn to a circle with radius $5cm$, from a point $13cm$ from the centre of the circle.

• A. $42cm$
• B. $22cm$
• C. $12cm$
• D. $10cm$

Answer 1

The correct option is C $12cm$

From the given figure,

Length of tangent $l=\sqrt{d^2-r^2}$

Here, $d=13cm,r=5cm$

$\therefore l=\sqrt{{13}^2-5^2}$

$=\sqrt{169-25}$

$=\sqrt{144}$

$=12cm$ (Ans)