Rectangle is a regular quadrilateral with four sides and four vertices. Opposite sides of rectangle are equal and parallel to each other. Each of its angle is right angle ([latex]90^circ[/latex]). As all the angles of rectangle are equal so its also called equiangular quadrilateral. Since, a rectangle is a 2-D shaped quadrilateral, it is characterized by two dimensions, length, and width. Length is the longer side of the rectangle and width is the shorter side. Diagonals of the length of the diagonals is equal. The two diagonals of rectangle bisect each other and divide the rectangle into two equal parts.

Area of  Rectangle

Area of a square is the number of unit squares needed to fill in a square. It is simply defined as the area or the space occupied by it. Area of calculated in square units i.e. square centimeters, square meters, square inch, square feet etc or simply square units. let us understand the concept more clearly with the following figure. Here rectangle is divided into squares of sides 1 units each.

We know that area is measured in square units. So count the number of squares in the above rectangle. There are 20 squares. So, the area of the rectangle is 20 square units. Now let us learn the formula to find the area of rectangle.

Area of Rectangle Formula

We discussed above that rectangle is 2 dimensional figure, so its sides as length and width.  In above example area of rectangle with length 5 units and width 4 units is 20 square units. So we have 5 x 4 = 20. Thus area of rectangle is length x width (breadth). Formula for area of rectangle can be written as A= l x b, where A is area, l is length and b is breadth (width).

Points to calculate area of rectangle

1. Note the values of length and breadth.
2. Find the product of length and breadth. values.
3. Mention the result as area in square units.

Example 1: Find the area of a rectangular floor whose dimensions are 15 m and 10 m.

Solution:

Length of rectangular floor = 15 m

Breadth of rectangular floor = 10 m

Area of rectangle = Length x Breadth

= 15 x 10

=  150 [latex]{m}^2[/latex]

Example 2: Calculate the area of a rectangle whose sides are 12.5 cm and 15.5 cm.

Solution:

Length of rectangle = 15.5 cm

Breadth of rectangle = 12.5 cm

Area of rectangle = Length x Breadth

= 15.5 x 12.5

=  193.75 [latex]{cm}^2[/latex]

Formula to calculate Length and Breadth.

Using the above formula to calculate are of rectangle, we can also find length and breadth. Lets how to find both one by one.

Length Formula

In this case to find length of rectangle, area and breadth must be known. To calculate length, divide area of rectangle with its breadth.

So the formula is ; Length = Area ÷ Breadth

or l = A ÷ b

Now let us understand the formula with example:

Example: Find the length of a rectangular sheet whose area is 12 square units and breadth is 3 units.

Solution:

Area of rectangular sheet given = 12 square units.

Breadth of rectangular sheet = 3 units

length = Area ÷ breadth

l = 12 ÷ 3

= 4 units

Breadth Formula

In this case to find breadth of rectangle, area and length must be known. To calculate breadth divide area of rectangle with its length.

So the formula is : Breadth = Area ÷ Length

or b = A ÷ l

Now let us understand the formula with examples:

Example: Find the breadth of a rectangular plane whose area is 2100 sq cm and length is 70 cm.

Solution:

Area of rectangular sheet given = 2100 sq cm.

Length of rectangular sheet = 70 cm

breadth = Area ÷ length

b = 2100 ÷ 70

= 30 cm

This concludes the topic how to find area of rectangle. Students are advised to practice more questions to clear the concept.