Question

The length of the tangent to a circle from a point p , which is 25 cm away from the centre , is 24 cm . What is the radius of the circle?

Answer 1

$$OP=25cm,QP=24cm$$

$$OQ \perp PQ$$
$$\therefore PQ^{2} + OQ^{2} = OP^{2} $$
$$(25)^{2} = OQ^{2}+ 24^{2}$$
$$OQ^{2} = 625 - 576$$
$$OQ = \sqrt{49}$$
$$OQ = 7 cm $$