question_answer

Chord AB of a circle when ex- tended meets the tangent to the circle at point P. PT is the tangent touching the circle at point T. If lengths of FT and PB are 6 cm. and 4 cm. respectively, what is the length of PA?

A)  12 cm.

B)  18 cm.

C)  27 cm.

D)  9 cm.

Correct Answer: D

Solution :

  \[PB.PA=P{{T}^{2}}\] \[\Rightarrow \]\[4\times PA=P{{T}^{2}}\] \[\Rightarrow \]\[PA=\frac{6\times 6}{4}=9\,cm.\]