A square is a four-sided polygon, known as a quadrilateral, where all sides are of equal length. Each of the four angles in a square measures 90 degrees, making it a type of rectangle as well. The properties of a square include symmetry and equal diagonals, which bisect each other at right angles. In mathematics, the area of a square can be calculated by squaring the length of one of its sides, represented as side². The perimeter, or the total distance around the square, is found by adding the lengths of all four sides, which can be expressed as 4 × side.