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AreA

Area is the amount of surface that a plane-closed B
figure covers. Look at the two posters shown
alongside. Which poster is bigger? Why? A
It is clear that poster (B) is bigger because it is taking SAve
up more space than poster (A). In other words, we SAve eArth
can say that poster B has more area than poster A. treeS
To measure the area of a closed figure drawn on a
square grid, we count the squares with a convenient unit of area.

Units of Area

Consider a square whose side is 1 cm. Its area would be the surface enclosed 1 cm
within its four sides. We say that its area is 1 square centimetre or 1 sq. cm. 1 cm 1 cm
Square centimetre or sq. cm is a unit of area. 1 cm
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 kilometre or 1 sq. km.
Now, look at the figure of a rectangle given below. FACTS
Divide it into squares of 1 cm each. This rectangle can What is an acre? You often
be covered by 7 squares of area 1 sq. cm each. hear land measured in ‘acres’.
An acre was originally the
amount of land that one man
1 cm with one ox could plough in one
day. Today, it’s standardized
Therefore, the area of this rectangle is 7 sq. cm. to 4,046.86 square metres.
Area of a rectangle

Let us consider a rectangle whose length is 6 cm and breadth is 4 cm.
Divide it into squares of side 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 Math Insight
Area of rectangle Measure of area means
Length = the number of square units
Breadth
Area of rectangle needed to exactly cover a
Breadth = closed 2D shape without
Length overlapping.

That is, A = (l × b) sq. units.
A
A
It also follows that, l = units and b = units.
b l
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