A point P is 26 cm from the centre of a circle of radius 10 cm. How long is a tangent drawn from P to the circle?

Explanation

1. 01

   The radius to the point of contact is perpendicular to the tangent, so the radius, the tangent and the line to the centre make a right triangle.

2. 02

   Tangent length = $\sqrt{26^2 - 10^2} = \sqrt{676 - 100} = \sqrt{576} = 24$ cm.