- Perimeter and Area
- Home
- Perimeter of a Polygon
- Perimeter of a Square or a Rectangle
- Area of a Square or a Rectangle
- Perimeter and Area on a Grid

- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who

# Perimeter of a Polygon

A **polygon** is a 2-dimensional figure formed by straight sides. The polygon with least number of sides is the triangle. Squares, rectangles, parallelograms, trapezoids are four sided polygons. A polygon with five sides is called a pentagon and a polygon of eight sides is called an octagon and so on.

A polygon with all sides equal and all angles equal is a **regular** polygon, otherwise it is an **irregular** polygon.

The **perimeter** of the polygon is the sum total of the lengths of its sides.

**Formula**

If the length of side of a regular polygon of *n* sides is *l*, then its perimeter is given by *nl*

Find the perimeter of the given polygon.

### Solution

**Step 1:**

The perimeter of any shape is the sum of the lengths of its sides.

**Step 2:**

So perimeter of given polygon =

8 cm + 8 cm + 10 cm + 10 cm + 7 cm = 43 cm

If the length of side of a regular polygon of 8 sides is 6 m, then find its perimeter.

### Solution

**Step 1:**

The length of side of a regular polygon of 8 sides = 6 m,

**Step 2:**

Perimeter of regular polygon = *nl* = no. of sides × length of its side

= 8 × 6 m = 48 m