Question

Draw a circle of radius 3 cm. Extend its diameter and mark two points P and Q each at a distance of 7 cm from the centre. From the points P and Q, draw tangents to the circle and find their approximate lengths.

Answer 1

Tangents can be constructed to the given circle as follows.

1. Draw a circle of 3 cm radius and mark its centre as O.

2. Extend diameter of the circle to a distance of 7 cm from centre on both sides.

3. Let these points be P and Q. Where OP = OQ = 7 cm.

4. Bisect OP and OQ. Let M and N be the mid-points of OP and OQ respectively.

5. Taking M as centre and MO as radius, draw a circle. Similarly taking N as centre and NO as radius draw a circle. Let it intersect at points A, B and C, D respectively.

6. Join PA, PB, PC and PD

7. Thus, PA, PB, QC, QD are the required tangents. PA = PB = PC = PD = 6.3 cm (approx)