Construct a regular hexagon of side 4 cm. Construct a circle circumscribing the hexagon.

Steps of construction :

1. Draw a line segment AB = 4 cm.

2. At A and B, draw rays making an angle of 120° each and cut off AF = BC = 4 cm.

3. Again from F and C, draw rays making an angle of 120° each and cut off FE = CD = 4 cm.

4. Join DE. Thus, ABCDEF is the regular hexagon.

5. Draw diagonals AD and FC. Let it meet at point O.

6. With O as center and OA as radius draw a circle passing through A, B, C, D, E and F.

Hence, above is the required circumcircle of regular hexagon.