Perimeter of Heptagon
2026-02-28 13:07 Diff

240 Learners

Last updated on September 26, 2025

The perimeter of a shape is the total length of its boundary. The sum of all seven sides is called the perimeter of a heptagon. Perimeter is also used for fencing a property, sewing, and more. In this topic, we will learn about the perimeter of a heptagon.

What is the Perimeter of a Heptagon?

The perimeter of a heptagon is the total length of its seven sides. By adding the length of all seven sides, we get the perimeter of the shape.

The formula for the perimeter of a heptagon is 𝑃 = 𝑎 + 𝑏 + 𝑐 + 𝑑 + 𝑒 + 𝑓 + 𝑔, where a, b, c, d, e, f, and g are the sides of the heptagon.

For instance, if a heptagon has sides a = 4, b = 5, c = 6, d = 7, e = 8, f = 9, and g = 10, then its perimeter is p = 4 + 5 + 6 + 7 + 8 + 9 + 10 = 49.

Formula for Perimeter of Heptagon - 𝑃 = 𝑎 + 𝑏 + 𝑐 + 𝑑 + 𝑒 + 𝑓 + 𝑔.

Let’s consider another example of a heptagon with side lengths, 𝑎 = 3, 𝑏 = 4, 𝑐 = 5, 𝑑 = 6, 𝑒 = 7, 𝑓 = 8, and 𝑔 = 9.

So the perimeter of the heptagon will be: 𝑃 = 𝑎 + 𝑏 + 𝑐 + 𝑑 + 𝑒 + 𝑓 + 𝑔 = 3 + 4 + 5 + 6 + 7 + 8 + 9 = 42.

How to Calculate the Perimeter of Heptagon

To find the perimeter of a heptagon, we just need to apply the given formula and sum all the sides of the heptagon.

For instance, a given heptagon has sides of a = 2, b = 2, c = 3, d = 3, e = 4, f = 4, g = 5. Perimeter = sum of all sides = 2 + 2 + 3 + 3 + 4 + 4 + 5 = 23 cm. Example Problem on Perimeter of Heptagon 

For finding the perimeter of a heptagon, we use the formula, 𝑃 = 𝑎 + 𝑏 + 𝑐 + 𝑑 + 𝑒 + 𝑓 + 𝑔.

For example, let’s say, a = 7 cm, b = 6 cm, c = 5 cm, d = 4 cm, e = 3 cm, f = 2 cm, and g = 1 cm.

Now, the perimeter = sum of all sides = 7 + 6 + 5 + 4 + 3 + 2 + 1 = 28 cm

Therefore, the perimeter of the heptagon is 28 cm.

Explore Our Programs

Tips and Tricks for Perimeter of Heptagon

Learning some tips and tricks makes it easier for children to calculate the perimeter of heptagons.

Here are some tips and tricks given below:

  • Always remember that a heptagon's perimeter is simply the sum of the seven sides of the shape. For that, use the formula, 𝑃 = 𝑎 + 𝑏 + 𝑐 + 𝑑 + 𝑒 + 𝑓 + 𝑔.
     
  • Calculating the perimeter of a heptagon starts by determining the length of each side using the distance formula.
     
  • The distance formula is: Distance = √((x2-x1)² + (y2-y1)²).
     
  • Here, (x1, y1) and (x2, y2) indicate the positions of two points that make out a heptagon’s side.
     
  • They can be found by adding the lengths of seven sides after they are calculated.
     
  • To reduce the confusion, specifically arrange the indicated side lengths if you need the perimeter of a group of heptagons. After that, apply the formula to each heptagon.
     
  • To avoid mistakes when adding the perimeter, make sure the side lengths are precise and constant for common uses like gardening and architecture.
     
  • If you are given the semi-perimeter, which is half the perimeter, you can multiply it by 2 to determine the full perimeter.
     
  • Area-related calculations often use the semi-perimeter.

Common Mistakes and How to Avoid Them in Perimeter of Heptagon

Did you know that while working with the perimeter of a heptagon, children might encounter some errors or difficulties? We have many solutions to resolve these problems. Here are some given below:

Problem 1

A garden plot is in the shape of a heptagon with a perimeter of 56 meters, and six of its sides each measure 7 meters. To find out the missing side, subtract the sum of the known sides from the total perimeter.

Okay, lets begin

Length of the missing side = 14 meters.

Explanation

Let ‘g’ be the side of the missing side.

And the given perimeter = 56 meters.

Length of the six equal sides = 7 meters each.

Perimeter of heptagon = sum of lengths of seven sides.

56 = 7 + 7 + 7 + 7 + 7 + 7 + g

56 = 42 + g

g = 56 – 42

= 14

Therefore, the missing side is 14 meters.

Well explained 👍

Problem 2

A rope with a perimeter of 140 meters is reshaped into a regular heptagon. Find the length of each side of the heptagon by dividing the total length by 7.

Okay, lets begin

20 meters

Explanation

Given that the perimeter of the rope is equal to the perimeter of the heptagon formed, here is the solution:

Perimeter of the rope = Total length of the rope Length of the rope used = Perimeter of the heptagon formed

Perimeter of a regular heptagon = 7 × a

140 = 7 × a

140 ÷ 7 = 20 a

= 20

Therefore, the length of each side of the heptagon is 20 meters.

Well explained 👍

Problem 3

Find the perimeter of a regular heptagon whose sides are 11 cm.

Okay, lets begin

77 cm

Explanation

Perimeter of regular heptagon = 7 × a

P = 7 × 11

= 77

Therefore, the perimeter of the heptagon is 77 cm.

Well explained 👍

Problem 4

Lucy is designing a heptagonal flower bed in her backyard. She measures the seven sides of the bed: Side A = 5 meters Side B = 4 meters Side C = 6 meters Side D = 5 meters Side E = 7 meters Side F = 4 meters Side G = 6 meters How much fencing should Lucy buy to go around the edge of the flower bed?

Okay, lets begin

Lucy will need 37 meters of fencing to go around the flower bed.

Explanation

The perimeter of a heptagon is the sum of all the seven sides.

Using the formula: P = a + b + c + d + e + f + g

P = 5 + 4 + 6 + 5 + 7 + 4 + 6 = 37 meters.

Well explained 👍

Problem 5

Find the perimeter of the irregular heptagonal rock.

Okay, lets begin

Sides are a = 3, b = 5, c = 4, d = 6, e = 2, f = 5, g = 4 Perimeter = a + b + c + d + e + f + g = 3 + 5 + 4 + 6 + 2 + 5 + 4 = 29 meters.

Explanation

Each side of the irregular heptagon has a different length.

The entire distance is calculated around the rock to be 29 meters by summing the lengths of the seven sides.

Well explained 👍

FAQs on Perimeter of Heptagon

1.Evaluate the heptagon’s perimeter if its sides are 2cm, 3cm, 4cm, 5cm, 6cm, 7cm, and 8cm.

Perimeter of heptagon = a + b + c + d + e + f + g, Hence p = 2 + 3 + 4 + 5 + 6 + 7 + 8 = 35 cm.

2.What is meant by a heptagon’s perimeter?

The total length around a heptagon’s sides is its perimeter. In other words, the perimeter of a heptagon is the total length of its sides.

3.What are the types of heptagons?

Heptagons can be regular, with all sides and angles equal, or irregular, with sides and angles of different measures.

4.Which heptagon has all equal sides?

A regular heptagon is a heptagon with all equal sides.

5.How do you find the perimeter of a heptagon when given the side lengths?

Add up the length of all seven sides to find the perimeter of a heptagon.

Important Glossaries for Perimeter of Heptagon

  • Perimeter: The total length of the sides of a shape.
  • Heptagon: A polygon with seven sides and seven angles.
  • Regular Heptagon: A heptagon with all sides and angles equal.
  • Irregular Heptagon: A heptagon with sides and angles of different lengths and measures.
  • Formula of perimeter: The mathematical expression used to calculate the perimeter of a heptagon is 𝑃 = 𝑎 + 𝑏 + 𝑐 + 𝑑 + 𝑒 + 𝑓 + 𝑔.

What Is Measurement? 📏 | Easy Tricks, Units & 🎯 Fun Learning for Kids | ✨BrightCHAMPS Math

Seyed Ali Fathima S

About the Author

Seyed Ali Fathima S a math expert with nearly 5 years of experience as a math teacher. From an engineer to a math teacher, shows her passion for math and teaching. She is a calculator queen, who loves tables and she turns tables to puzzles and songs.

Fun Fact

: She has songs for each table which helps her to remember the tables