Page No 219:
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:
It is known that,Area of rectangle = Length × Breadth
(a) l = 3 cm
b = 4 cm
Area = l × b = 3 × 4 = 12 cm2
(b) l = 12 m
b = 21 m
Area = l × b = 12 × 21 = 252 m2
(c) l = 2 km
b = 3 km
Area = l × b = 2 × 3 = 6 km2
(d) l = 2 m
b = 70 cm = 0.70 m
Area = l × b = 2 × 0.70 = 1.40 m2
Question 2:
Find the areas of the squares whose sides are:(a) 10 cm (b) 14 cm (c) 5 m
Answer:
It is known that,Area of square = (Side)2
(a) Side = 10 cm
Area = (10)2 =100 cm2
(b) Side = 14 cm
Area = (14)2 = 196 cm2
(c) Side = 5 m
Area = (5)2 = 25 m2
Q 3 - Ex 10.3 - Mensuration - NCERT Maths Class 6th - Chapter 10
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:
It is known that,Area of rectangle = Length × Breadth
(a) l = 9 m
b = 6 m
Area = l × b = 9 × 6 = 54 m2
(b) l = 17 m
b = 3 m
Area = l × b = 17 × 3 = 51 m2
(c) l = 4 m
b = 14 m
Area = l × b = 4 × 14 = 56 m2
It can be seen that rectangle (c) has the largest area and rectangle (b) has the smallest area.
Q 4 - Ex 10.3 - Mensuration - NCERT Maths Class 6th - Chapter 10
Question 4:
The area of a rectangular garden 50 m long is 300 sq m. Find the width of the garden.Answer:
Let the breadth of the rectangular garden be b.l = 50 m
Area = l × b = 300 square m
50 × b = 300
b =
Q 5 - Ex 10.3 - Mensuration - NCERT Maths Class 6th - Chapter 10
Question 5:
What is the cost of tiling a rectangular plot of land 500 m long and 200 m wide at the rate of Rs 8 per hundred sq m?Answer:
Area of rectangular plot = 500 × 200 = 100000 m2Cost of tiling per 100 m2 = Rs 8
Cost of tiling per 100000 m2 =
= Rs 8000Q 6 - Ex 10.3 - Mensuration - NCERT Maths Class 6th - Chapter 10
Question 6:
A table-top measures 2 m by 1 m 50 cm. What is its area in square metres?Answer:
Length (l) = 2 mBreadth (b) = 1 m 50 cm =
Area = l × b = 2 × 1.5 = 3 m2
Q 7 - Ex 10.3 - Mensuration - NCERT Maths Class 6th - Chapter 10
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:
Length (l) = 4 mBreadth (b) = 3 m 50 cm = 3.5 m
Area = l × b = 4 × 3.5 = 14 m2
Q 8 - Ex 10.3 - Mensuration - NCERT Maths Class 6th - Chapter 10
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:
Length (l) = 5 mBreadth (b) = 4 m
Area of floor = l × b = 5 × 4 = 20 m2
Area covered by the carpet = (Side)2 = (3)2 = 9 m2
Area not covered by the carpet = 20 − 9 = 11 m2
Q 9 - Ex 10.3 - Mensuration - NCERT Maths Class 6th - Chapter 10
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 the land = 5 × 4 = 20 m2Area occupied by 5 flower beds = 5 × (Side)2 = 5 × (1)2 = 5 m2
∴ Area of the remaining part = 20 − 5 = 15 m2
Question 10:
By splitting the following figures into rectangles, find their areas (The measures are given in centimetres).
(a) (b)
Answer:
(a) The given figure can be broken into rectangles as follows.
Area of 2nd rectangle = 6 × 1 = 6 cm2
Area of 3rd rectangle = 3 × 2 = 6 cm2
Area of 4th rectangle = 4 × 2 = 8 cm2
Total area of the complete figure = 8 + 6 + 6 + 8 = 28 cm2
(b) The given figure can be broken into rectangles as follows.
Area of 2nd rectangle = 3 × 1 = 3 cm2
Area of 3rd rectangle = 3 × 1 = 3 cm2
Total area of the complete figure = 3 + 3 + 3 = 9 cm2
Q 11 - Ex 10.3 - Mensuration - NCERT Maths Class 6th - Chapter 10
Page No 220:
Question 11:
Split the following shapes into rectangles and find their areas. (The measures are given in centimetres)
Answer:
(a) The given figure can be broken into rectangles as follows.
Area of 1st rectangle = 12 × 2 = 24 cm2
Area of 2nd rectangle = 8 × 2 = 16 cm2
Total area of the complete figure = 24 + 16 = 40 cm2
(b) The given figure can be broken into rectangles as follows.
Area of 2nd square = 7 × 7 = 49 cm2
Area of 3rd square = 7 × 7 = 49 cm2
Total area of the complete figure = 147 + 49 + 49 = 245 cm2
(c) The given figure can be broken into rectangles as follows.
Area of 2nd rectangle = 4 × 1 = 4 cm2
Total area of the complete figure = 5 + 4 = 9 cm2
Q 12 - Ex 10.3 - Mensuration - NCERT Maths Class 6th - Chapter 10
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) Total area of the region = 100 × 144 = 14400 cm2Area of one tile = 12 × 5 = 60 cm2
Number of tiles required =
Therefore, 240 tiles are required.
(b) Total area of the region = 70 × 36 = 2520 cm2
Area of one tile = 60 cm2
Number of tiles required =
Therefore, 42 tiles are required.
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