Exercise 10.3

NCERT Solutions for Class 6 Mathematics Exercise 10.3

Exercise 10.1 Exercise 10.2 Exercise 10.3

NCERT Answers for Class 6 Maths Chapter 10 |
Mensuration Exercise 10.3

Page 219

Ex 10.3 Class 6 Maths Question 1. Find the areas of the rectangles whose sides are : (a) 3 cm and 4 cm (b) 12 m and 21 m (c) 2 km and 3 km (d) 2 m and 70 cm

Answer

We know that

Area of rectangle = Length × Breadth

(a) l = 3 cm and b = 4 cm

Area = l × b = 3 × 4

= 12 cm²

(b) l = 12 m and b = 21 m

Area = l × b = 12 × 21

= 252 m²

(c) l = 2 km and b = 3 km

Area = l × b = 2 × 3

= 6 km²

(d) l = 2 m and b = 70 cm = 0.70 m

Area = l × b = 2 × 0.70

= 1.40 m²

Ex 10.3 Class 6 Maths Question 2. Find the areas of the squares whose sides are :
(a) 10 cm (b) 14 cm (c) 5 m

Answer

(a) Area of square = side²

= 10²

= 100 cm²

(b) Area of square = side²

= 14²

= 196 cm²

(c) Area of square = side²

= 5²

=25 cm²

Ex 10.3 Class 6 Maths Question 3.The length and breadth of three rectangles are as given below :
(a) 9 m and 6 m (b) 17 m and 3 m (c) 4 m and 14 m

Which one has the largest area and which one has the smallest?

Answer

(a) Area of rectangle = l × b

= 9 × 6

= 54 m²

(b) Area of rectangle = l × b

= 17 × 3

= 51 m²

(c) Area of rectangle = l × b

= 4 × 14

= 56 m²

Area of rectangle 56 m² i.e (c) is the largest area and area of rectangle 51 m² i.e (b) is the smallest area

Ex 10.3 Class 6 Maths Question 4. The area of a rectangular garden 50 m long is 300 sq m. Find the width of the garden.

Answer

Area of rectangle = length × width

300 = 50 × width

width = 300 / 50

width = 6 m

Therefore, the width of the garden is 6 m

Ex 10.3 Class 6 Maths Question 5. What is the cost of tiling a rectangular plot of land 500 m long and 200 m wide at the rate of ₹ 8 per hundred sq m.?

Answer

Area of land = length × breadth

= 500 × 200

= 1,00,000 m²

Therefore, cost of tiling 1,00,000 sq m of land = (8 × 1,00,000) / 100

= ₹ 8000

Ex 10.3 Class 6 Maths Question 6. A table-top measures 2 m by 1 m 50 cm. What is its area in square metres?

Answer

Given

l = 2m

b = 1m 50 cm = 1.50 m

Area = l × b = 2 × 1.50

= 3 m²

Ex 10.3 Class 6 Maths Question 7. A room is 4 m long and 3 m 50 cm wide. How many square metres of carpet is needed to cover the floor of the room?

Answer

Given

l = 4m

b = 3 m 50 cm = 3.50 m

Area = l × b = 4 × 3.50

=14 m

Ex 10.3 Class 6 Maths Question 8. A floor is 5 m long and 4 m wide. A square carpet of sides 3 m is laid on the floor. Find the area of the floor that is not carpeted.

Answer

Area of floor = l × b = 5 × 4

= 20 m²

Area of square carpet = 3 × 3

= 9 m²

Area of floor that is not carpeted = 20 – 9

= 11 m²

Therefore, area of the floor that is not carpeted is 11 m²

Ex 10.3 Class 6 Maths Question 9. Five square flower beds each of sides 1 m are dug on a piece of land 5 m long and 4 m wide. What is the area of the remaining part of the land?

Answer

Area of flower square bed = 1 × 1

= 1 m²

Area of 5 square bed = 1 × 5

= 5 m²

Area of land = 5 × 4

= 20 m²

Remaining part of the land = Area of land – Area of 5 square bed

= 20 – 5

= 15 m²

Therefore, remaining part of the land is 15 m²

Ex 10.3 Class 6 Maths Question 10. By splitting the following figures into rectangles, find their areas (The measures are given in centimetres).

Answer

(a)

Area of HKLM = 3 x 3 = 9 cm²
Area of IJGH = 1 x 2 = 2 cm²
Area of FEDG = 9 cm²
Area of ABCD = 2 x 4 = 8 cm²
Total area of the figure = 9 +2 + 9 +8 = 28 cm²

(b)

(b) Area of ABCD = 3 x 1 = 3 cm²
Area of BDEF = 3 x 1 = 3 cm²
Area of FGHI 3 x 1 = 3 cm²
Total area of the figure = 3 + 3 + 3 = 9 cm²

Ex 10.3 Class 6 Maths Question 11. Split the following shapes into rectangles and find their areas. (The measures are given in centimetres)

Answer

(a)

Area of rectangle ABCD = 2 x 10 = 20 cm²
Area of rectangle DEFG = 10 x 2 = 20 cm²
Total area of the figure = 20 + 20 = 40 cm²

(b)

There are 5 squares each of side 7 cm.
Area of one square = 7 x 7 = 49 cm²
Area of 5 squares = 49 x 5 = 245 cm²

(c)

Area of rectangle ABCD = 5 x 1 = 5 cm²
Area of rectangle EFGH = 4 x 1 = 4 cm²
Total area of the figure = 5 + 4 cm²

Ex 10.3 Class 6 Maths Question 12. How many tiles whose length and breadth are 12 cm and 5 cm respectively will be needed to fit in a rectangular region whose length and breadth are respectively: (a) 100 cm and 144 cm (b) 70 cm and 36 cm.

Answer

(a) Area of rectangle = 100 × 144

= 14400 cm

Area of one tile = 5 × 12

= 60 cm²

Number of tiles = (Area of rectangle) / (Area of one tile)

= 14400 / 60

= 240

Hence, 240 tiles are needed

(b) Area of rectangle = 70 × 36

= 2520 cm²

Area of one tile = 5 × 12

= 60 cm²

Number of tiles = (Area of rectangle) / (Area of one tile)

= 2520 / 60

= 42

Hence, 42 tiles are needed