Perimeter Formulas

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Introduction

This page contains the formula for area of a:

Examples are given to show you how to use the formulas.

Have fun practicing perimeter questions by downloading our free Zapzapmath Home Grade 3 app and playing Fency Farm:
Apple App Store (iOS) | Google Play (Android)

Square

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Formula

The lesson on the perimeter of a square will provide the explanation and examples needed to understand this formula. Here's the summary:

All the sides (edges) of a square have the same length. If each side has the length L, the formula for the preimeter P will be:

P = 4L
square with the sides L
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Example

Given a square where the side lengths are 3cm. Find the perimeter of this square.

Using the formula for the perimeter of a square

Rectangle

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Formula

The lesson on the perimeter of a rectangle will cover the basics needed to use this formula. Here's a short summary:

If a rectangle has the length l and the width w, the perimeter P, will be:

formula for the perimeter of a rectangle
rectangle with width w and length l
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Example

Given a rectangle with the length of 5ft and the width of 3ft. Find its perimeter.

Using the formula for the perimeter of a rectangle

Triangle

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Formula

The lesson on the perimeter of a triangle will explain the basics behind this formula. Here's the summary:

For a triangle with the side lengths of a, b and c, its perimeter P, will be:

formula for the perimeter of a triangle
a circle with the radius r
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Example

Given a triangle with the side lengths of 3cm, 4cm and 5cm. Find the perimeter of the triangle.

Using the formula for the perimeter of a triangle

Parallelogram

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Formula

The lesson on the perimeter of a parallelogram will explain the basics. Here's the summary:

For a parallelogram with the side lengths of a and b, its perimeter P, will be:

formula for the perimeter of a parallelogram
a parallelogram with the base b and height h
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Example

Given a parallelogram with the side lengths of 8 inches and 6 inches. Find the perimeter of this parallelogram.

Using the formula for the perimeter of a parallelogram

Have fun practicing perimeter questions by downloading our free Zapzapmath Home Grade 3 app and playing Fency Farm:
Apple App Store (iOS) | Google Play (Android)