A secant PAB is drawn from an external point P to the circle with centre O, intersecting it at A and B. If OP = 17 cm, PA = 12 cm, and PB = 22.5 cm, then the radius of the circle is:
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. √19 cm
By using the tangent secant theorem,
PC2 = PA × PB
PC2 = 12 × 22.2 = 270
In POC,
OP2 = OC2 + PC2
289 - 270 = OC2
OC = cm.