draw a circle of radius 4cm with centre O. Draw a diameter POQ. Through Pdraw a tangent to the circle.

Follow the given steps to construct a tangent to the circle.

Step 1: Take a point O on the plane of the paper and draw a circle of radius OP = 4 cm.

Step 2: Draw the diameter POQ.

Step 3: Construct ∠PQT = 90°.

Here, PT is the tangent to the circle at P.               (Radius is perpendicular to the tangent at point of contact)