Question

A person is standing at P outside a circular ground at a distance of 26 m from the centre of the ground. He found that his distances from the points A and B on the ground are 10 m (PA and PB are tangents to the circle). Find the radius of the circular ground.

Answer 1

Using the Pythagoras Theorem in the right-angled triangle △POA:

PO² = OA² + PA²

26² = r² + 10²

676 = r² + 100

r² = 576

r = 24

Thus, the radius of the circular ground is 24 m.