Page 175 - Start Up Mathematics_5

Let’s now find the area of some plane figures using a squared sheet of paper where the area
of each square is 1 square unit.

Example 6: Find the area of the given figure.

Solution: Number of squares covered = 25
Area of 1 square = 1 square unit

Area of 25 squares = 25 × 1 square unit
= 25 square units

Example 7: Find the area of rectangle ABCD.
A B
Solution: There are 6 squares in each horizontal line and
4 squares in each vertical line.
So, the area of ABCD = 6 × 4 square units

= 24 square units D C

Example 8: Find the approximate area of the given
figure. Mental Maths
Find the area of the given figure.
= 1 cm 2

Solution: Number of full squares = 11
Number of half squares = 2 = 1 full square

Number of more than ½ squares = 1 = 1 full square
Number of less than ½ squares = 1 = 0 square
Approximate area = (11 + 1 + 1) square units = 13 square units

Remember

1. If the shape covers ½ a square, the area is taken as ½ square unit.
2. If the shape covers more than ½ a square, the area is taken as 1
square unit.
3. If the shape covers less than ½ a square, then that square is left out.

Example 9: Find the approximate area of the given figure.

1
Solution: Area = 6 × square units + 29 square units
2
= (3 + 29) square units
= 32 square units

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