Page 152 - ICSE Math 5

Count the number of square tiles that cover the rectangular board. Since there are 14 square
tiles covering the board, the area of the board is 14 cm .
2
Now we know that the rectangular board measuring 7 cm and 2 cm has an area of 14 cm .
2
Observe that the number of tiles that covered the rectangular board is the product of its length
and breadth. Therefore, to calculate the area of a rectangle, we use the following formula.

Area of a rectangle = Length × Breadth

We can also find the length and breadth of a rectangle by using the following formula.

Top Tip
Area
Length of a rectangle =
Breadth The length and breadth
should have the same
Area
Breadth of a rectangle = units to calculate the area
Length of a rectangle.

Example 9: Find the area of a rectangular wall that is 20 m in length and 14 m in breadth.

Solution: Length of the rectangular wall (l) = 20 m

Breadth of the rectangular wall (b) = 14 m
 Area of the rectangular wall (A) = l × b = 20 × 14 = 280 m 2
So, the area of the rectangular wall is 280 m .
2
Example 10: If the area of a rectangular park is 10 m and its length is 5 m, find its breadth.
2
Solution: Area of the rectangular park (A) = 10 m 2
Length of the rectangular park (l) = 5 m
Area 10 m 2
 Breadth of the rectangular park (b) = = = 2 m
Length 5 m
So, the breadth of the rectangular park is 2 m.

Area of a Square

Look at the figure given alongside.
D 4 units E
In the given square DEFG, all the sides DE, EF, FG and GD are of equal
lengths, i.e., each side measures 4 units. Each small square in the
given figure has an area of 1 square unit. Let’s find the total area of
the given figure.

On counting the number of small squares, it is clear that the area of
the given figure is 16 square units. G F
We know that all the sides of a square are equal in length, therefore, to calculate the area of a
square, we use the following formula.

Area of a square = Side × Side

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