How many axes of symmetry does a square have?

If the transformation of symmetry with respect to some straight line transforms the figure into itself, then this figure is called symmetric with respect to this straight line, and this straight line is called the axis of symmetry of the figure.
Thus, the lines on which the diagonals of the square lie are its axes of symmetry. There are two such axes.
And the straight lines passing through the intersection point of the diagonals of the square parallel to its sides are also the axes of symmetry of the square. There are also two such axes.
Thus, a square has four axes of symmetry.