For other uses, see Square (disambiguation).

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 .

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

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

## Formulas

If the length of side *a* is known, then we have that:

Perimeter | |

Area | |

Length of diagonal |

If the length of diagonal *d* is known, then we have that:

Length of side | |

Perimeter | |

Area |

## Related pages

## Images for kids

All content from Kiddle encyclopedia articles (including the article images and facts) can be freely used under Attribution-ShareAlike license, unless stated otherwise. Cite this article:

Square Facts for Kids. *Kiddle Encyclopedia.*