Question

The length of a tangent from a point $A$ at distance $5cm$ from the circle of the circle $4cm$. Find the radius of the circle.

Answer 1

The length of the tangent AP is cm and the distance of point A from the centre of the circle is 5 cm.

In $\Delta AOP$,

$r^2={\left(5\right)}^2-{\left(4\right)}^2$

$r^2=25-16$

$r=3cm$

Therefore, the radius of the circle is 3 cm.