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Last updated on September 8, 2025

Perimeter of Square Rectangle

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

Perimeter of Square Rectangle for US Students
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What is the Perimeter of a Square Rectangle?

The perimeter of a square rectangle is the total length of its four sides. By adding the length of all four sides, we get the perimeter of the shape.

 

The formula for the perimeter of a square rectangle is 𝑷 = 2𝑙 + 2𝑀, where 𝑙 is the length and 𝑀 is the width of the rectangle.

 

For instance, if a rectangle has a length of 6 and a width of 8, then its perimeter is 𝑃 = 2(6) + 2(8) = 28.

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Formula for Perimeter of Square Rectangle - 𝑷 = 2𝑙 + 2𝑀.

Let’s consider another example of a square rectangle with a length of 8 and a width of 10.

 

So the perimeter of the square rectangle will be: 𝑷 = 2𝑙 + 2𝑀 = 2(8) + 2(10) = 16 + 20 = 36.

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How to Calculate the Perimeter of Square Rectangle

To find the perimeter of a square rectangle, we just need to apply the given formula and sum twice the length and twice the width of the rectangle.

 

For instance, a given rectangle has a length of 6 and a width of 6. Perimeter = 2𝑙 + 2𝑀 = 2(6) + 2(6) = 24 cm.

 

Example Problem on Perimeter of Square Rectangle -

 

For finding the perimeter of a square rectangle, we use the formula, 𝑷 = 2𝑙 + 2𝑀.

 

For example, let’s say, 𝑙 = 5 cm and 𝑀 = 4 cm.

 

Now, the perimeter = 2(5) + 2(4) = 10 + 8 = 18 cm.

 

Therefore, the perimeter of the square rectangle is 18 cm.

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Tips and Tricks for Perimeter of Square Rectangle

Learning some tips and tricks makes it easier for children to calculate the perimeter of square rectangles. Here are some tips and tricks given below:

 

  • Always remember that a square rectangle's perimeter is simply the sum of twice the length and twice the width of the shape. For that, use the formula, 𝑷 = 2𝑙 + 2𝑀.

 

  • Calculating the perimeter of a square rectangle 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 rectangle’s side.

 

  • They can be found by adding the lengths of the sides after they are calculated. To reduce confusion, specifically arrange the indicated side lengths if you need the perimeter of a group of rectangles. After that, apply the formula to each rectangle.

 

  • 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.
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Common Mistakes and How to Avoid Them in Perimeter of Square Rectangle

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

Mistake 1

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Incorrectly using the formula for square shapes when calculating the perimeter of rectangles.

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Remember that a square is a special type of rectangle where all sides are equal. Always use the perimeter formula for rectangles, 𝑷 = 2𝑙 + 2𝑀, unless it is a square.

Mistake 2

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Students may confuse the concepts of area and perimeter, leading to incorrect calculations.

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It is important to note that the perimeter, calculated in linear units, is the total length of the rectangle’s sides, while the area, in square units, represents the space inside the rectangle.

Mistake 3

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Assuming that every rectangle is a square, which results in inaccurate calculations.

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A rectangle can have different lengths and widths. Always be careful about the shape's type to ensure accurate calculations.

Mistake 4

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Using the wrong values for the length and width, misreading a problem, or mislabeling the sides.

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Double-check the problem and ensure that you're using the correct lengths and widths for your rectangle.

Mistake 5

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Misunderstanding or misidentifying the side lengths that are given in a problem outline.

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Before starting the calculations, make sure that you understand the problem and, if it's possible, try to draw a rectangle to accurately identify the side lengths.

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Perimeter of Square Rectangle Examples

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Problem 1

A rectangular garden has a perimeter of 48 inches and one side measures 17 inches. To find out the missing side of the garden, subtract the sum of the known sides multiplied by 2 from the total perimeter.

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Length of the missing side = 7 inches.

Explanation

Let ‘w’ be the missing side of the garden. And the given perimeter = 48 inches.

 

Length of one side = 17 inches.

 

Perimeter of rectangle = 2𝑙 + 2𝑀. 48 = 2(17) + 2𝑀 48 = 34 + 2𝑀 2𝑀 = 48 – 34 = 14 𝑀 = 14 ÷ 2 = 7

 

Therefore, the missing side is 7 inches.

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Problem 2

A wire with a perimeter of 200 inches is reshaped into a square rectangle where the length equals the width. Find the length of each side of the square and divide the total length by 4.

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50 inches

Explanation

Given that the perimeter of the rectangle is equal to the total length of the wire and this wire is reshaped into a square, here is the solution:

 

Perimeter of the rectangle = Total length of the wire

 

Length of the wire used = Perimeter of the square formed

 

Perimeter of a square = 4 × π‘Ž 200 = 4 × π‘Ž 200 ÷ 4 = 50 π‘Ž = 50

 

Therefore, the length of each side of the square is 50 inches.

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Problem 3

Find the perimeter of a square where each side is 10 cm.

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40 cm

Explanation

Perimeter of square = 4 × side P = 4 × 10 = 40

 

Therefore, the perimeter of the square is 40 cm.

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Problem 4

Annie is planning a rectangular vegetable garden in her backyard. She measures the two sides of the garden: Length = 12 meters Width = 9 meters How much string should Annie buy to go around the edge of the garden?

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Annie will need 42 meters of string to go around the garden.

Explanation

The perimeter of a rectangle is the sum of twice the length and twice the width.

 

Using the formula: P = 2𝑙 + 2𝑀 P = 2(12) + 2(9) = 24 + 18 = 42 meters.

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Problem 5

Find the perimeter of a rectangular rock.

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Length = 10, Width = 7 Perimeter = 2𝑙 + 2𝑀 = 2(10) + 2(7) = 20 + 14 = 34 meters.

Explanation

Each side of the rectangle has a different length and width. The entire distance is calculated around the rock to be 34 meters by summing twice the lengths and widths.

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FAQs on Perimeter of Square Rectangle

1.Evaluate the rectangle’s perimeter if its length is 3 cm and the width is 4 cm.

Perimeter of rectangle = 2𝑙 + 2𝑀, Hence p = 2(3) + 2(4) = 6 + 8 = 14 cm.

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

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

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3.What are the types of rectangles?

There are two main types of rectangles: Square (where all sides are equal) and non-square rectangles (where opposite sides are equal).

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4.Which rectangle has equal sides?

A square is a rectangle with all sides equal. All four sides of the square are of the same length.

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5.Which rectangle has the smallest perimeter for a given area?

For a given area, a square has the smallest perimeter compared to other rectangles with the same area.

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Important Glossaries for Perimeter of Square Rectangle

  • Perimeter: The total length of the boundary of a shape.

 

  • Square Rectangle: A rectangle with all sides equal, also known as a square.

 

  • Formula for perimeter: The mathematical expression used to calculate the perimeter of a rectangle is 𝑷 = 2𝑙 + 2𝑀.

 

  • Length: The longer side of a rectangle.

 

  • Width: The shorter side of a rectangle.
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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.

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Fun Fact

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

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