Property that is applied to a geometric figure by which this figure remains unchanged by a given rotation.

Synonym for invariant by a rotation.

### Examples

- A square ABCD remains unchanged by a rotation of a multiple of 90° around its centre of gravity O.
- A sphere remains unchanged by a rotation around its centre of gravity, which is the centre of the sphere.

- A rectangle remains unchanged by a rotation of 180° around the intersection point of its diagonals.
- A regular pentagon remains unchanged by a rotation of a multiple of 72° around its center of gravity.