Search

NCERT Solutions for Class 7 Maths: Chapter 11 - Perimeter and Area

NCERT Solutions for Class 7 Maths (Chapter 11 - Perimeter and Area) are available here. With this article, you can access solutions for all the answers of Class Maths NCERT Textbook, Chapter 11.

Jul 3, 2020 12:57 IST
facebook IconTwitter IconWhatsapp Icon
NCERT Solutions for Class 7 Maths: Chapter 11 -  Perimeter and Area
NCERT Solutions for Class 7 Maths: Chapter 11 - Perimeter and Area

NCERT Solutions for Class 7 Maths (Chapter 11 - Perimeter and Area) are available here. With this article, you can access solutions for all the answers of Class Maths NCERT Textbook, Chapter 11. This chapter is one of the most important chapters of Class 7 Maths NCERT textbook and students must prepare this chapter well to secure good marks in the exam.

NCERT Book for Class 7 Mathematics (PDF): Hindi & English (New Edition)

NCERT Solutions for Class 7 Maths: Chapter 11 -  Perimeter and Area

EXERCISE 11.1

1. The length and the breadth of a rectangular piece of land are 500 m and 300 m respectively. Find

(i) its area

(ii) the cost of the land, if 1 m2 of the land costs Rs. 10,000.

Solutions:

(i) Area = (Length × Breadth= 500 × 300 = 1,50,000 m2

(ii) As, Cost of 1 m2 land = Rs. 10000

So, cost of 1,50,000 m2 land = 10,000 × 1,50,000 = Rs. 1,500,000,000

2. Find the area of a square park whose perimeter is 320 m.

Solutions:

Given, Perimeter = 320 m

Now, Perimeter = 4 × Length of the side of park = 320

Also, length of the side of the park = 320/4 = 80 m

Therefore, area = (Length of the side of the park)2 = (80)2 = 6400 m2

3. Find the breadth of a rectangular plot of land, if its area is 440 m2 and the length is 22 m. Also find its perimeter.

Solutions:

Given, Area = 440 m2

Also, Area = Length × Breadth

So, 22 × Breadth = 440

Or Breadth = 440/22 = 20 m

Now, Perimeter = 2 (Length + Breadth) = 2 (22 + 20) = 2 (42) = 84 m.

4. The perimeter of a rectangular sheet is 100 cm. If the length is 35 cm, find its breadth. Also find the area.

Solutions:

Given, Perimeter = 100 cm

Also, Perimeter = 2 (Length + Breadth) 

So, 2 (35 + Breadth) = 100

 35 + Breadth = 50

 Breadth = 50 − 35 = 15 cm

Now, Area = Length × Breadth = 35 × 15 = 525 cm2

5. The area of a square park is the same as of a rectangular park. If the side of the square park is 60 m and the length of the rectangular park is 90 m, find the breadth of the rectangular park.

Solutions:

Given side of the square park is 60 m 

So, area of square park = (Side)2 = (60)2 = 3600 m2

Now, area of rectangular park = Length × Breadth = 3600

 90 × Breadth = 3600

 Breadth = 40 m

6. A wire is in the shape of a rectangle. Its length is 40 cm and breadth is 22 cm. If the same wire is rebent in the shape of a square, what will be the measure of each side. Also find which shape encloses more area?

Solutions:

According to the question, Perimeter of rectangle = Perimeter of square

Perimeter of rectangle = 2 (Length + Breadth) & Perimeter of square =  4 × Side

So, according to the question, we have, 2 (Length + Breadth) = 4 × Side

 2 (40 + 22) = 4 × Side

 2 × 62 = 4 × Side

 Side = 124/4 = 31 cm

 Area of rectangle = 40 × 22 = 880 cm2

 Area of square = (Side)2 = 31 × 31 = 961 cm2

Clearly, the square-shaped wire encloses greater area.

7. The perimeter of a rectangle is 130 cm. If the breadth of the rectangle is 30 cm, find its length. Also find the area of the rectangle.

Solutions:

Given, Perimeter = 2 (Length + Breadth) = 130

 2 (Length + 30) = 130

 Length + 30 = 65

 Length = 65 − 30 = 35 cm

So, Area = Length × Breadth = 35 × 30 = 1050 cm2

8. A door of length 2 m and breadth 1m is fitted in a wall. The length of the wall is 4.5 m and the breadth is 3.6 m (Fig11.6). Find the cost of white Fig 11.6 washing the wall, if the rate of white washing the wall is Rs. 20 per m2.

Solutions:

Given, the length of the wall is 4.5 m and the breadth is 3.6 m

So, area of wall = 4.5 × 3.6 = 16.2 m2

Also, area of door = 2 × 1 = 2 m2

Now, Area to be white-washed = 16.2 − 2 = 14.2 m2

Given, cost of white-washing of 1 m2 area = Rs. 20

∴ Cost of white-washing 14.2 m2 area = 14.2 × 20 = Rs. 284.

Solutions of exercises 11.1, 11.2, 11.3, 11.4 will be available shortly.

Related Stories