## Perimeter formulas for Circle, Square, Rectangle, Triangle and more.

### What is a Perimeter?

In Geometry, the definition of Perimeter is the complete distance around that two dimensional figure. As per International System of Units (SI Units) the unit to measure the Perimeter is same as the unit of the length provided.

#### Rectangle

A Rectangle is a two dimensional shape having 4 sides. The opposite sides of rectangle have the same lenghts and parallel.

The longer side is called as length and the smaller side is called as width.

The Perimeter of the Rectangle is calculated as;

Perimeter of the Rectangle = 2(length + width)

#### Square

A Square is also a two dimensional shape having 4 sides. Compare to Rectangle, the sides of the Square are same.

The Perimeter of the Square is calculated as;

Perimeter of the Square = 4 x side

#### Triangle

A Triangle is a two dimensional shape having 3 sides. Triangle can be categorized based on the length of its sides;

• Equilateral triangle - having all sides are same in length.
• Isosceles triangle - having two sides are in same length and another side having different length.
• Scalene triangle - all sides are in different length.
• The Perimeter of the Triangle is calculated as;

Perimeter of the Triangle = a + b + c
a,b,c = three sides of the Triangle

#### Circle

A Circle is simple closed two dimensional shape having no corners. The distance from the center point of the circle to any point in its perimeter is same and it is called as radius.

The Perimeter of the Circle is calculated as;

Perimeter of the Circle = 2πR

#### Sector

A Sector is basically a proportion of a circle. It is having two sides as radius and one side as arc. Given the radius and the angle the Perimeter of the Sector can be calculated.

The Perimeter of the Sector is calculated as;

Perimeter of the Sector = 2R x (angle/360) x 2πR

#### Parallelogram

A Parallelogram is having two pairs of parallel sides. Rectangle, Squares are the special cases of parallelogram.

The Perimeter of the Parallelogram is calculated as;

Perimeter of the Parallelogram = 2 x (base + height)

#### Ellipse

An Ellipse is a form of circle and a curve in a plane. It is having one Major axis and one Minor axis.

The Perimeter of the Ellipse is calculated as;

Perimeter of the Ellipse = 2π √(a2+b2)/2
a = Major axis
b = Minor axis