Rectangle Area and Perimeter Calculator

Area and Perimeter of a Rectangle Example 1

Find the area and perimeter of the rectangle below.

The length of rectangle is 12 cm and the width is 7 cm.

The area of a rectangle

\[ A = l \cdot w \; \] where l is the length and w is the width of the rectangle.

So if we substitute the values of the length and width into this equation, we get: \[ A = 12 \times 7 = 84 \]

The area of the rectangle is 84 cm².

The perimeter of a rectangle

\[ P = 2l + 2w \; \]

So if we substitute the values of the length and width into this equation, we get: \[ P = (2 \times 12) + (2 \times 7) = 24 + 14 = 38 \]

The perimeter of the rectangle is 38 cm.

Area and Perimeter of a Rectangle Example 2

Find the area and perimeter of the rectangle below.

The length of rectangle is 2.4 m and the width is 0.7 m.

The area of a rectangle

\[ A = l \cdot w \; \] where l is the length and w is the width of the rectangle.

So if we substitute the values of the length and width into this equation, we get: \[ A = 2.4 \times 0.7 = 1.68 \]

The area of the rectangle is 1.68 m².

The perimeter of a rectangle

\[ P = 2l + 2w \; \]

So if we substitute the values of the length and width into this equation, we get: \[ P = (2 \times 2.4) + (2 \times 0.7) = 4.8 + 1.4 = 6.2 \]

The perimeter of the rectangle is 6.2 m.

Area and Perimeter of a Rectangle Example 3

Find the area and perimeter of the rectangle below leaving your answer for the area as a mixed fraction.

Although this shape is tilted, it is still a rectangle.

The length of rectangle is 3 ½ inches and the width is 8 ½ inches.

The area of a rectangle

\[ A = l \cdot w \; \] where l is the length and w is the width of the rectangle.

So if we substitute the values of the length and width into this equation, we get: \[ A = 3 {1 \over 2} \times 8 {1 \over 2} = {7 \over 2} \times {17 \over 2} \]

Multiplying the fractions together gives us: \[ A = {7 \times 17 \over 2 \times 2} = {119 \over 4} = 29 {3 \over 4} \]

The area of the rectangle is 29 ¾ in².

The perimeter of a rectangle

\[ P = 2l + 2w \; \]

So if we substitute the values of the length and width into this equation, we get: \[ P = 2 \times 3 {1 \over 2} + 2 \times 8 {1 \over 2} = 7 + 17 = 24 \]

The perimeter of the rectangle is 24 inches.

Area and Perimeter of a Rectangle Example 4

Find the area and perimeter of the rectangle below. Give your answer in cm or cm².

The length of rectangle is 2.1 m and the width is 45 cm.

First we need to convert 2.1 m into cm so that both measurements have the same units of measure.

1 m = 100 cm so 2.1 m = 2.1 x 100 = 210 cm

The area of a rectangle

\[ A = l \cdot w \; \] where l is the length and w is the width of the rectangle.

So if we substitute the values of the length and width into this equation, we get: \[ A = 210 \times 45 = 9450 \]

The area of the rectangle is 9450 cm².

The perimeter of a rectangle

\[ P = 2l + 2w \; \]

So if we substitute the values of the length and width into this equation, we get: \[ P = (2 \times 210) + (2 \times 45) = 420 + 90 = 510 \]

The perimeter of the rectangle is 510 cm.

You can use our Rectangle area and perimeter calculator to check any of these examples out!