In a circle, AB is a the 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 is:
Answer & explanation
Correct answer: option 2
By using concept ,
PD × PC = PB × PA
15.3 × ( 15.3 + 11.9 ) = PB × 30.6
15.3 × 27.2 = PB × 30.6
PB = 13.6 cm
Now,
AB = AP - PB
= 30.6 - 13.6
= 17
Radius of the circle = \(\frac{AB}{2}\)
= \(\frac{17}{2}\)
= 8.5 cm