Question

In following fig., PT is a tangent to the circle at T and PAB is a secant to the same circle. If PB = 9cm and AB = Scm, find PT. 

Answer 1

Let PT = x cm 

Since, PAB is a secant and PT is a tangent to the given circle, we have, 

PA · PB = PT² 

⇒ 4 · 9 = PT² 

⇒ PT² = 36 

⇒  PT = 6cm