# Perimeter of a square

 Perimeter P = 4s

A side of the square = s
AB = BC = CD = DA

## Example

ABCD is a square with side s = 5 cm
Perimeter A of the square ABCD = 4s = 4 x 5 = 20 cm

## Calculate the perimeter of a square

 Side s Perimeter of the square

## Definition of a square

A square is a plane figure with four equal sides and four right (90°) angles.
A square is a quadrilateral that has 4 sides of the same length and 4 right angles.

To calculate the perimeter of a square, multiply one of its sides by 4.
The length of all the four sides of a square are equal, so the perimeter is four times the length of any side of a square.
The perimeter of a square is the total length of the four equal sides of the square.

## Properties of a square

A square has its diagonals of the same length, which intersect in their middle and are perpendicular.
A square has its opposite sides two by two parallel.
The diagonals of a square bisect each other at 90°.
The length of the diagonals of a square is equal.
The sum of all interior angles of a square is 360°.
All four sides of the square are equal to each other.
The opposite sides of a square are parallel to each other.

## To go further

A square is a quadrilateral, as it has 4 sides and 4 angles.
A square is a rectangle. Indeed it has 4 right angles.
A square is a rhombus. Indeed it has its 4 equal sides.
Since the sides of a square are parallel, a square is a parallelogram.

The perimeter of a square is the total length of all the sides of the square. Indeed we can find the perimeter of a square by adding all its four sides. The perimeter is the length of the outline of a shape. Multiply the side length of the square by four to find the perimeter. The perimeter of a square is the sum of the length of all four sides.