Question

Find the distance of point P from the centre of circle given the radius is 5 cm & length of tangent PA is 12 cm

• A. 9
• B. 18
• C. 7
• D. 13

Answer 1

The correct option is D

13

We need to find PO.

Radius (OA) is always perpendicular to tangent (PA)

We have $\angle PAO={90}^{\circ }$

Applying pythagoras theorem, we get

$O{P}^2=P{A}^2+O{A}^{2}P{O}^2=P{A}^2+O{A}^2\Rightarrow P{O}^2={12}^2+5^2=144+25=169PO=13$