# Perimeter Calculator

In the calculator below select the shape whose perimeter you want to learn, enter the desired dimensions and press the calculate button.

## What is perimeter?

It is the total length of the line which is bounding a shape on the plane.

## How is the perimeter of the rectangle calculated?

It is calculated by the formula below which expresses twice the sum of base width and height.

Perimeter of a Rectangle = a + a + h + h = 2 x (a + h)

## How to calculate the perimeter of the square?

A square is a rectangle with a base width and height of equal length. Since all sides of the square are equal to each other, its circumference is calculated by the formula below.

Perimeter of the Square = a + a + a + a = 4 x a

## How is the circumference of the circle calculated?

The circumference of the circle is calculated by the formula below.

Circumference of the Circle = 2 x π x r

## How to find the perimeter of triangles?

The perimeter of triangles is generally obtained by adding the lengths of the 3 sides.

The perimeter of equilateral triangles is calculated by the formula below which expresses the sum of the lengths of the three sides.

Circumference of an Equilateral Triangle = a + a + a = 3 x a

## What is the perimeter formula for a trapezoid?

It is determined by the following formula that the lengths of all sides of the trapezoid are summed up.

Perimeter of Trapezoid = a + b + c + d

## How to calculate the perimeter of regular polygons?

Since the lengths of all sides of regular polygons are equal to each other, the perimeter of polygons is calculated by the formula below which expresses the number of sides and the length of an edge.

Circumference of a Regular Polygon = Number of sides (n) x a = n x a

Circumference of a Regular Pentagon = 5 x a

Circumference of a Regular Hexagon = 6 x a

Circumference of a Regular Octagon = 8 x a