You have 15 seconds.
The symmetry group of a plane figure is defined as the set of all motions of that figure such that the figure is invariant under the motions - i.e., you put a circle in, you get a circle of the same size and shape, at the same place in the plane, back. How many elements are there in the symmetry group for a square centered at the origin? You have 15 seconds.
The symmetry group of a plane figure is defined as the set of all motions of that figure such that the figure is invariant under the motions - i.e., you put a circle in, you get a circle of the same size and shape, at the same place in the plane, back.
{8} (the identity, three rotations, and four reflections)