Class 7 Math NCERT SOLUTIONS FOR Chapter – 15 Visualizing Solid Shapes ex – 15.1

Visualizing Solid Shapes

1. Identify the nets which can be used to make cubes (cut out copies of the nets and try it):

(i)

NCERT Solutions for Class 7 Maths Chapter 15 Visualising Solid Shapes Image 1

Solution:-

The given net cannot be folded as cube.

Because, it can be folded as below,
NCERT Solutions for Class 7 Maths Chapter 15 Visualising Solid Shapes Image 2

(ii)

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Solution:-

The given net can be folded as cube.

Because, it can be folded as below,

NCERT Solutions for Class 7 Maths Chapter 15 Visualising Solid Shapes Image 4

(iii)

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Solution:-

The given net can be folded as cube.

Because, it can be folded as below,

NCERT Solutions for Class 7 Maths Chapter 15 Visualising Solid Shapes Image 6

(iv)

NCERT Solutions for Class 7 Maths Chapter 15 Visualising Solid Shapes Image 7

Solution:-

The given net can be folded as cube.

Because, it can be folded as below,

NCERT Solutions for Class 7 Maths Chapter 15 Visualising Solid Shapes Image 8

(v)

NCERT Solutions for Class 7 Maths Chapter 15 Visualising Solid Shapes Image 9

Solution:-

The given net cannot be folded as cube.

Because, it can be folded as below,

NCERT Solutions for Class 7 Maths Chapter 15 Visualising Solid Shapes Image 10

(vi)

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Solution:-

The given net can be folded as cube.

Because, it can be folded as below,

NCERT Solutions for Class 7 Maths Chapter 15 Visualising Solid Shapes Image 12

2. Dice are cubes with dots on each face. Opposite faces of a die always have a total of seven dots on them.

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Here are two nets to make dice (cubes); the numbers inserted in each square indicate the number of dots in that box.

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Insert suitable numbers in the blanks, remembering that the number on the opposite faces should total to 7.

Solution:-

(i)

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By observing the above figure the sum of the opposite faces is equal to 7.

So, the given net can be folded into a net of dice.

(ii)

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By observing the above figure the sum of the opposite faces is equal to 7.

So, the given net can be folded into a net of dice.

3. Can this be a net for a die?

Explain your answer.

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Solution:-

The given net is folded as dice is shown in figure below,

NCERT Solutions for Class 7 Maths Chapter 15 Visualising Solid Shapes Image 18

No, this cannot be a net for a die.

By observing the figure we can say that, one pair of opposite face will have 1 and 4, another pair of opposite face will have 3 and 6 the sum of these two opposite faces are not equal to 7.

4. Here is an incomplete net for making a cube. Complete it in at least two different ways. Remember that a cube has six faces. How many are there in the net here?

(Give two separate diagrams. If you like, you may use a squared sheet for easy manipulation.)

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Solution:-

In the given net there are 3 faces and it can be completed as shown below,

NCERT Solutions for Class 7 Maths Chapter 15 Visualising Solid Shapes Image 20

5. Match the nets with appropriate solids:

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Solution:-

(a) (ii)

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Because, the net (ii) can be folded as square.

(b) (iii)

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Because, the net (iii) can be folded as cylinder.

(c) (iv)

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Because, the net (iv) can be folded as cone.

(d) (i)

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Because, the net (i) can be folded as pyramid.