# NCERT Solutions for Class 7 Maths Chapter 13 Visualising Solid Shapes

NCERT Solutions for Class 7 Maths Chapter 13 Visualising Solid Shapes is the best study material, which provides solutions to all the questions present in the NCERT Class 7 textbook. Students can refer to these NCERT Solutions and practise various questions daily to perform well in the final exams.

**Exercise 13.1 **

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

**(i)**

**Solution:-**

The given net cannot be folded as a cube.

Because it can be folded as below,

**(ii)**

**Solution:-**

The given net can be folded as a cube.

Because it can be folded as below,

**(iii)**

**Solution:-**

The given net can be folded as a cube.

Because, it can be folded as below,

**(iv)**

**Solution:-**

The given net can be folded as a cube.

Because it can be folded as below,

**(v)**

**Solution:-**

The given net cannot be folded as a cube.

Because it can be folded as below,

**(vi)**

**Solution:-**

The given net can be folded as a cube.

Because, it can be folded as below,

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

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

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

**Solution:-**

**(i)**

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)**

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.**

**Solution:-**

The given net is folded as dice as 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 faces will have 1 and 4, and another pair of opposite faces 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?**

**NCERT Solutions For Class 7 Maths Chapter 12 Symmetry**

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

**Solution:-**

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

**5. Match the nets with appropriate solids:**

**Solution:-**

**(a) (ii)**

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

**(b) (iii)**

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

**(c) (iv)**

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

**(d) (i)**

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

**Exercise 13.2 **

**1. Use isometric dot paper and make an isometric sketch for each one of the given shapes:**

**(i)**

Solution:-

**(ii)**

**Solution:-**

**(iii)**

**Solution:-**

**(iv)**

**Solution:-**

**2. The dimensions of a cuboid are 5 cm, 3 cm and 2 cm. Draw three different isometric sketches of this cuboid.**

**Solution:-**

From the question it is given that the dimensions of a cuboid are 5 cm, 3 cm, and 2 cm.

The three different isometric sketches of this cuboid are shown below,

1

2

**3**

**3. Three cubes each with a 2 cm edge are placed side by side to form a cuboid. Sketch an oblique or isometric sketch of this cuboid.**

**Solution:-**

Oblique sketch

Isometric sketch

**4. Make an oblique sketch for each one of the given isometric shapes:**

**(i)**

**Solution:-**

**(ii)**

**Solution:-**

**5. Give (i) an oblique sketch and (ii) an isometric sketch for each of the following:**

**(a) A cuboid of dimensions 5 cm, 3 cm and 2 cm. (Is your sketch unique?)**

**(b) A cube with an edge 4 cm long.**

**Solution:-**

(a)

**(i) **Oblique sketch

**(ii)** Isometric sketch

(b)

**(i) **Oblique sketch

**(ii)** Isometric sketch

**Exercise 13.3 **

**1. What cross-sections do you get when you give a**

**(i) vertical cut (ii) horizontal cut**

**to the following solids?**

**(a) A brick**

**Solution:-**

The cross-section of a brick when it is cut into vertically is as shown in the figure below,

The cross-section of a brick when it is cut horizontally is as shown in the figure below,

**(b) A round apple**

**Solution:-**

The cross-section of a round apple when it is cut into vertically is as shown in the figure below,

The cross-section of a round apple when it is cut into horizontally is as shown in the figure below,

**(c) A die**

**Solution:-**

The cross-section of a die when it is cut into vertically is as shown in the figure below,

The cross-section of a die when it is cut horizontally is as shown in the figure below,

**(d) A circular pipe**

**Solution:-**

The cross-section of a circular pipe when it is cut vertically is shown in the figure below,

The cross-section of a circular pipe when it is cut into horizontally is as shown in the figure below,

**(e) An ice cream cone**

**Solution:-**

The cross-section of an ice cream when it is cut into vertically is as shown in the figure below,

The cross-section of an ice cream when it is cut into horizontally is as shown in the figure below,

**Exercise 13.4**

**1. A bulb is kept burning just right above the following solids. Name the shape of the shadows obtained in each case. Attempt to give a rough sketch of the shadow. (You may try to experiment first and then answer these questions).**

**(i)**

**Solution:-**

The shape of the shadow obtained from a ball is a circle.

**(ii)**

**Solution:-**

The shape of the shadow obtained from a cylindrical pipe is a rectangle.

**(iii)**

**Solution:-**

The shape of the shadow obtained from a book is a rectangle.

**2. Here are the shadows of some 3-D objects, when seen under the lamp of an overhead projector. Identify the solid(s) that match each shadow. (There may be multiple answers for these!)**

**(i)**

**Solution:-**

Cricket ball, water bottle cap, Disc

**(ii)**

**Solution:-**

Die, chalk box etc.

**(iii)**

**Solution:-**

Birthday cap etc.

**(iv)**

**Solution:-**

Book, keyboard, mobile, etc.

**3. Examine if the following are true statements:**

**(i) The cube can cast a shadow in the shape of a rectangle.**

**Solution:-**

The above statement is true.

**(ii) The cube can cast a shadow in the shape of a hexagon.**

**Solution:-**

The above statement is false.