# How to Find the Area of a Rectangle (Mathematics Lesson)

# How to Find the Area of a Rectangle

The area of a rectangle is found using the 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:

# A Real Example of How to Find the Area of a Rectangle

#### An Example Question

What is the area of a rectangle with a base of 8 cm and a height of 5 cm, as shown below?Step 1

Start with the formula:
Area = bh

**Don't forget:**bh = b × h

Step 2

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

The area of the rectangle with a base of 8 cm and a height of 5 cm is 40 cm^{2}^{2}.

# Another Real Example of How to Find the Area of a Rectangle

The slider below shows another real example of how to find the area of a rectangle:##### Curriculum

##### Interactive Test

**show**

Here's a second test on finding the area of a rectangle.

Here's a third test on finding the area of a rectangle.

##### Note

# 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 length^{2}. (All areas are lengths squared.)

This affects the units used. If the lengths of a rectangle are in cm, the area is in cm

^{2}. If the lengths are in inches, the area is in inches

^{2}.