Chapter 13: Fields and Fences

Q1Written answer

A square has a boundary of 12 cm.

(a) From the corner of this square, a small square of side 1 cm is cut off. Will the boundary of B be less or more? Find its length.

(b) If you cut a 1 cm square to get shape C, what will be the length of the boundary of C?

NCERT Solutions for Class 4 Chapter 13 Image 15

Show solutionHide solution

Worked solution

(a) We know that the boundary of shape B is equal to the boundary of shape C.

So the boundary of shape B = 12 cm

(b) Here, the boundary of shape C will be equal to 14 cm.

Q2Written answer

(a) Find the length of the boundary of square D.

(b) 8 squares of side 1 cm are cut out of square D. Now it looks like shape E. What is the length of the boundary of shape E?

(c) The boundary of this is ___ + ___ + ___ + ___

Can we also say that the boundary is 4 × 1 cm?

Show solutionHide solution

Worked solution

(a) The length of the boundary of square D = 5 + 5 + 5 + 5 = 20 cm

(b) We know that there are 21 edges measuring 1 cm in shape E

Therefore, the boundary of shape E = 1 × 21 = 21 cm

(c) The boundary of this
NCERT Solutions for Class 4 Chapter 13 Image 18 is 1 + 1 + 1 + 1 = 4 cm

Here, the boundary of
NCERT Solutions for Class 4 Chapter 13 Image 19 = 4 × 1 cm.

NCERT Textbook Page No. – 156

Q3Written answer

A hockey field is 91 metres 40 cm long and 55 metres wide. How long is the boundary of the field?

Show solutionHide solution

Worked solution

We know that the length of the field = 91 m 40 cm

It can be written as

= 9100 + 40

= 9140 cm

Width of the field = 55 m = 55 × 100 = 5500 cm

Here

Boundary = length + width + length + width

Substituting the values

= 9140 + 5500 + 9140 + 5500

= 29280 cm

= 292 m 80 cm

Q4Written answer

Usha and Valsamma are running a race. Usha is running on the inner circle. Valsamma is running on the outer circle.

Valsamma runs faster than Usha. But still she loses the race. Can you guess why?

Show solutionHide solution

Worked solution

We know that the inner circle has a shorter boundary when compared to the outer circle.

Valsamma runs on the outer circle and has to cover more length.

Hence, Valsamma loses the race.

Q5Written answer

Have you seen any race where runners start from different places – like in this picture? Guess why?

NCERT Solutions for Class 4 Chapter 13 Image 21

Show solutionHide solution

Worked solution

Yes, I have seen the race, which is organized on a circular track. It is made in such a manner to make the distances equal.

NCERT Textbook Page No. – 157

School Garden

The students of Class III and IV thought of making a vegetable garden. They chose a place which looked like this.

Students of both the classes though that garden 1 was bigger. So both wanted to take garden 1. Suddenly Neetu said –

Q1 (2)Written answer

1. How will Neetu find out if the two gardens are equally big?

Show solutionHide solution

Worked solution

First, Neetu places a long rope along the boundary of garden 1 to measure the length.

Again she places the rope along the boundary of garden 2 to measure the length.

Then she found that the boundaries of both the gardens are equal.

Therefore, both gardens are equal.

NCERT Textbook Page No. – 158

My Cart

Your Cart 0

Practice Time (2)