In a circle, AB is diameter and CD is a chord, AB and CD produced meet at a point P, outside the circle. If PD = 15.3 cm, CD = 11.9 cm and AP = 30.6 cm, then the radius of the circle is:
Show answer & explanation
Correct answer: C
Explanation
The correct answer is Option 3 i.e 8.5 cm
We know that,
AP × BP = CP × DP
⇒ 30.6 × BP = 27.2 × 15.3
⇒ BP = 416.16/30.6
⇒ BP = 13.6
So,
AB = AP - BP = 30.6 - 13.6 = 17 cm
Hence,
Radius = AB/2 = 17/2 = 8.5 cm