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\\November 22, 2023 5:10 PM Surender Prajapati Proof 5 Reader _________________________ Date: ___________________74

If the side of a square is 1 m, then the unit of area is 1 square metre or 1 sq. m.
Similarly, if the side of a square is 1 km, the unit of area is 1 square kilometer or 1 sq. km.

Now, look at the figure of a rectangle given to the right side.
Divide it into squares of 1 cm each. This rectangle can be
covered by 7 squares of area 1 sq. cm each. 1 cm
Therefore, the area of this rectangle is 7 sq. cm.

Area of a rectangle

Let us consider a rectangle whose length is 6 cm and breadth is 4 cm.
Divide it into squares whose side is 1 cm. 6 cm

Now, count the number of squares in the rectangle.
Here, number of squares = 24 4 cm
So, the area of rectangle = area of 24 unit squares

= 24 × 1 sq. cm = 24 sq. cm
= (6 × 4) sq. cm

= 6 cm × 4 cm (length = 6 cm and breadth = 4 cm)
Therefore, Area of a rectangle = (Length × Breadth) sq. units Remember

Area of rectangle
And Length = Measure of area means
Breadth the number of square units
Area of rectangle needed to exactly cover a
And Breadth =
Length closed 2D shape without
overlapping.
That is, A = (l × b) sq. units.
A
A
It also follows that, l = units and b = units.
b l
example 1: Find the area of a rectangular postcard whose length is 18 cm and breadth is
12 cm. 18 cm

Solution: Here, length of the postcard = 18 cm POSTCARD
from:
and breadth of the postcard = 12 cm 12 cm

Area of the postcard = Length × Breadth to:
= 18 cm × 12 cm = 216 sq. cm
example 2: Area of a rectangle is 1680 sq. cm and its length is 60 cm. Find its breadth.

Solution: Given, area of the rectangle = 1680 sq. cm
and length of the rectangle = 60 cm.

Area 1680 sq. cm
Since, breadth of rectangle = = = 28 cm
Length 60 cm
Thus, breadth of the rectangle is 28 cm.
teacher’s Ensure that the students understand the difference between perimeter and area. An area is the measure of
tip the interior region of a closed plane figure, while perimeter is the measure of its boundary. The area and
perimeter of an open plane figure has no meaning.

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