Square

A square is a shape with four equal sides and four corners that are all right angles (90 degrees). The diagonals of a square also cross at right angles. The angle between any diagonal and a side of a square is 45 degrees. A square has rotational symmetry of four. It has four lines of regular symmetry. A square with vertices A, B, C and D can be written as ${\displaystyle \square ABCD}$.^[1][2]

A square is a type of rectangle with all sides of equal length. However, while a square is a type of rectangle and rhombus,^[3] the opposite does not need to be true.

A square is also the 2-dimensional analogue of a cube.