Answer:

When a shape can be mapped onto itself by a rotation of less than 360^o it is said to have rotational symmetry.

The flower with 5 petals, for example, can be rotated about its center to map onto itself through an angle of 1/5th of a turn and any multiple of this angle, so it is said to have rotational symmetry of order 5.

The box shaped like a hexagonal prism, can be rotated about its main axis through an angle of 1/6th of a turn and any multiple of this angle, so it has rotational symmetry of order 6 about this axis.

Generally we can make out, an object with rotational symmetry is an object that looks the same after a certain amount of rotation.