A circle with radius r has a tangent line at a point P on the circle. The distance of the tangent from point P to the external point Q is 10 cm. The distance from the center of the circle to point Q is 13 cm. Find the radius of the circle.
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. .
OQ = 13 cm
PQ = 10 cm
Here, ∠OPQ = 90°
By Pythagoras: OQ2 = OP2 + PQ2
⇒ 132 = r2 + 102
⇒ 169 = r2 + 100
⇒ r2 = 69
⇒ r = √69 cm