### Theory:

*Working rule to construct a tangent to a circle (Using the centre)*:

Given the radius of a circle, let us learn how to construct a tangent to the circle using its centre.

Example:

Draw a circle of radius \(3\) \(cm\). Take a point \(P\) on this circle and draw a tangent at \(P\).

**:**

*Rough Sketch*Construction:

**: Draw a circle with centre at \(O\) of radius \(3\) \(cm\).**

*Step \(1\)***: Take a point \(P\) on the circle and join \(OP\).**

*Step \(2\)***: Draw perpendicular line \(TT'\) to \(OP\) which passes through \(P\).**

*Step \(3\)***: \(TT'\) is the required tangent.**

*Step \(4\)*