Area of a Rectangle
(KS3, Year 7)

homegeometryfinding the area of a rectangle
The area of a rectangle is found using the formula:

area rectangle formula In this formula, b is the length of the base of the rectangle and h is the height of the rectangle. The image below shows what we mean by the length of the base and the height:

rectangle bh

How to Find the Area of a Rectangle

Finding the area of a rectangle is easy.


What is the area of a rectangle with a base of 8 cm and a height of 5 cm, as shown below? area of rectangle example



Start with the formula:
Area = bh
Don't forget: bh = b × h


Substitute the length of the base and the height into the formula. In our example, b = 8 and h = 5.
Area = 8 × 5 = 40 cm2


The area of the rectangle with a base of 8 cm and a height of 5 cm is 40 cm2.

"Find the Area" Widget

Here is a widget to help you learn the formulas to find the areas of different shapes.
  • Click on the shape you're learning about.
  • Click on the pad to start.
  • Follow the instructions in the bottom-left corner.
  • On the last click, the formula, workings, and answer will appear in the yellow box.
  • Enjoy!
full page

Lesson Slides

The slider below shows another real example of how to find the area of a rectangle.

What Is a Rectangle?

A rectangle is a flat shape with four straight sides and four right angles. The opposite sides are parallel and of equal length. Adjacent sides are perpendicular and of unequal length.

A Note on Units

The area of a rectangle is a length times a length, so we say its dimension is length2. (All areas are lengths squared). This affects the units used. If the lengths of a rectangle are in cm, the area is in cm2. If the lengths are in inches, the area is in inches2.
author logo

This page was written by Stephen Clarke.

You might also like...

Help Us Improve Mathematics Monster

  • Do you disagree with something on this page?
  • Did you spot a typo?
Please tell us using this form.

Find Us Quicker!

  • When using a search engine (e.g., Google, Bing), you will find Mathematics Monster quicker if you add #mm to your search term.

Share This Page

share icon

If you like Grammar Monster (or this page in particular), please link to it or share it with others.

If you do, please tell us. It helps us a lot!

Create a QR Code

create QR code

Use our handy widget to create a QR code for this page...or any page.