Important points:
1. Regular polygons have equal sides and equal angles.
2. Rotation = turns an object about a fixed point.
3. Centre of rotation = fixed point around which object rotates
4. Angle of rotation = Angle by which the object rotates
5. Half-turn = rotation by 180o
6. Quarter-turn = rotation by 90o
7. Rotational symmetry = after rotation the object looks same
8. Order of rotational symmetry = in 360o rotation, number of times the object looks the same
