A tangent is drawn from a point M to a circle, which meets the circle at T such that MT = 12 cm. a secant MAB intersects the circle at points A and B. If MA = 8 cm, what is the length (in cm) of the chord AB ?

Length of the tangent MT = 12 cm

Length MA = 8 cm

According to the tangent-secant theorem (or power of a point theorem), if a tangent and a secant are drawn from an external point to a circle, the square of the length of the tangent is equal to the product of the external part of the secant and the entire length of the secant.

​$$MT^2 = MA \times MB$$​​

Solution: