February 23, 2024
Finding perimeter is an important concept in mathematics. This article provides a comprehensive guide with step-by-step instructions and examples of how to calculate perimeter for different shapes. Additionally, it highlights the real-life applications of perimeter, compares it with other geometric concepts, and provides tips and tools to remember it better.

Finding Perimeter: A Step-by-Step Guide

Perimeter is a fundamental concept in mathematics. It is the length of the boundary of a two-dimensional shape and is a crucial measurement in various real-life applications. Whether you need to calculate the length of a fence for your garden, the distance around a running track, or the amount of wire required for an electrical circuit, knowing how to find perimeter is essential. This guide is here to help you understand the concept of perimeter and how to calculate it for different shapes.

Step-by-Step Guide

Perimeter is the total distance around the outer edge of a two-dimensional shape. The formula to calculate perimeter depends on the shape you are dealing with:

  • For squares, the perimeter is four times the length of one side (P = 4s).
  • For rectangles, the perimeter is twice the sum of the length and width (P = 2(l + w)).
  • For triangles, the perimeter is the sum of the lengths of all three sides.
  • For irregular shapes, it is best to break them down into simpler shapes and calculate each section’s perimeter separately and then add them together.

Let’s look at an example:


Let’s say we have a triangle with sides 6 cm, 8 cm, and 10 cm. To find the perimeter, all we need to do is add the lengths of all three sides together:

Perimeter = 6 cm + 8 cm + 10 cm = 24 cm

It’s that simple! Now let’s look at some other examples.


A square has four equal sides. To calculate its perimeter, you need to multiply the length of one side by four:


Perimeter = 4 x 5 = 20 units


Unlike squares, rectangles have two pairs of equal sides, but the length and width are usually different. To calculate the perimeter of a rectangle, you need to add the length of all four sides together:


Perimeter = 2(5 + 8) = 26 units

Irregular shapes

Irregular shapes can be any shape and size, so it is best to break down the shape into simpler shapes like triangles, rectangles, or squares, and then add them together. Suppose you have an irregular shape like the one below:

irregular shape

Firstly you need to measure all the sides of the shape, like this:

measuring sides

Then you should break the shape down into simpler shapes:

break down shape

Next, calculate the perimeter of each simpler shape and add them together to get the perimeter of the entire shape:

Perimeter of rectangle = 2(5 + 3) = 16 units

Perimeter of triangle = 3 + 4 + 5 = 12 units

Perimeter of trapezoid = 2 + 5 + 3 = 10 units

Entire perimeter = 16 + 12 + 10 = 38 units

Real-Life Applications

The importance of perimeter is demonstrated in numerous real-life applications, such as:

  • Fencing around a garden or park
  • Building sports fields, tracks or courts
  • Constructing buildings and houses
  • Calculating the length of wiring required for electrical circuits

It is essential to calculate the perimeter accurately in such applications to ensure that you have the correct amount of materials required for the job, which can save you both time and money in the long run.

Comparison with Other Geometrical Concepts

Perimeter is often confused with other geometric concepts like area and volume. However, there are some key differences to note:

  • Perimeter: It is the length of the boundary of a two-dimensional shape and measures in units such as centimeters or inches.
  • Area: It is the measure of the extent of a two-dimensional shape and is measured in square units like cm² or in².
  • Volume: It is the measure of the amount of space that a three-dimensional shape occupies and is measured in cubic units such as cm³ or in³.

While all three concepts are important, they are distinct measurements that are not directly interchangeable.

Interactive Tools

If you find it difficult to remember the formulas and equations to calculate the perimeter, you can use interactive tools and online calculators to help visualize these concepts. The following website calculator.bz provides an online calculator to help calculate the perimeter of various basic shapes.

Please click https://calculator.bz/perimeter-calculator

This calculator allows you to input various shapes and measurements and instantly get the perimeter. With this tool, you can compare different shapes’ perimeters and practice various shapes to gain a better understanding of the concept.

Tips to Remember

While calculating the perimeter is a straightforward concept, it can be easy to forget the formulas and equations. Here are some tips to help you remember how to calculate perimeter:

  • Try memorizing the formulas for the most common shapes such as squares and rectangles.
  • Create mnemonic devices to help you remember the formulas.
  • Practice regularly by calculating the perimeter of different shapes and in real-life scenarios.


Understanding perimeter is essential for various real-life applications, and knowing how to calculate it accurately can save time and money. By following the step-by-step guide and using tools such as online calculators, practice, and memory devices, you can master the concept of perimeter calculation and apply this knowledge to different real-life problems.

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