Chord AB and diameter CD of a circle meet at the point P, outside the circle when produced. If PB = 8 cm, AB = 12 cm and the distance of P from the centre of the circle is 18 cm, the radius (in cm) of the circle is closest to :
Answer & explanation
Correct answer: option 1
By using secant property :-
PA × PB = PC × PD
Let us consider that , Radius of circle = a cm
( 12 + 8 ) × 8 = ( 18 - a ) × ( 18 + a )
160 = 18² - a²
a² + 160 = 324
a² = 164
a = 4√41
= 12.8