. . "A geometric object has symmetry if there is an \"operation\" or \"transformation\" (technically, an isometry or affine map) that maps the figure/object onto itself; i.e., it is said that the object has an invariance under the transform. For instance, a circle rotated about its center will have the same shape and size as the original circle\u2014all points before and after the transform would be indistinguishable. A circle is said to be symmetric under rotation or to have rotational symmetry."@en . . . . .