A figure in a plane has rotational symmetry if the figure can be mapped onto itself by a rotation between $0^{\circ }$ and $360^{\circ }$ about the center of the figure. This point is called the center of symmetry. When a figure has rotational symmetry, it is said to be rotationally symmetric. As shown, a square, an equilateral triangle, and the digit $0$ all have rotational symmetry, each with a particular angle measure. The order of symmetry of a figure is the number of times it maps onto itself while rotating from $0^{\circ }$ to $360^{\circ }.$