NCERT Solution for Class 7th Maths Exercise – 15.1 Chapter – 15 Visualising solid Shapes

Q1. Identify the nets which can used to make cubes

Solution:-

The given net cannot be folded as cube.

Because , it can be folded as below,

(ii)

Solution:-

The given net can be folded as cube.

Because,it can be folded as below,

(iii)

Solution:-

The given net can be folded as cube.

Because , it can be folded as below,

(iv)

Solution:-

The given net can be folded as cube.

Because it can be folded as below,

(v)

Solution:-

The given net cannot be folded as cube,

Because, it can be folded as below,

(vi)

Solution:-

The given net can be folded as cube.

Because, it can be folded as below,

Q2. Dice are cubes with dots on each face. Opposite faces of a lie always have a total of seven dots on them.

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

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

Solution:-

(i)

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

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

(ii)

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

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

Q3. Can this be a net for a die ? Explain your answer.

Solution:-

The given net is folded as dice is shown in the figure below.

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.

Q4. 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 that net here?

Solution:-

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

Q5. Match the nets with appropriate solids:

Solution:-

(a)(ii)

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

(b)(iii)

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

( c )(iv)

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

(d)(i)

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