Question

A point P is 13 cm from the centre of the circle. The length of the tangent drawn from P to the circle is 12 cm. Find the radius of the circle.​

Answer 1

Answer:

Since tangent to a circle is perpendicular to the radius through the point of contact.

∴∠OTP=90'

In right triangle OTP, we have

OP^2 = OT^2 + PT^2

⇒13^2 = OT^2 + 12^2

⇒OT^2 = 13^3 − 12^2

⇒(13−12)(13+12)

⇒OT=5.

Hence, radius of the circle is 5 cm.