# NCERT Solutions for Class 7 Mathematics Chapter 14 - Visualising Solid Shapes

##### Question 1:

Complete the following table: Complete table is as follow: ##### Question 2:

Here you find four nets (Figure). There are two correct nets among them to make a tetrahedron. See if you can work out which nets will make a tetrahedron. In given figures part (i) and part (iii) are two correct nets for a tetrahedron.

##### Question 3:

Identify the nets which can be used to make cubes (cut out copies of the nets and try it): Nets in (ii), (iii), (iv) and (vi) form cubes.

##### Question 4:  ##### Question 5: Reason: Because one pair of opposite faces will have 1 and 4 on them whose total is not 7 and another pair of opposite faces will have 3 and 6 on them whose total is also not 7.

##### Question 6:

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).  ##### Question 7:

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

Dimensions of cuboid are 5 cm, 3 cm and 2 cm. By changing length, breadth and height, we get three different isometric sketches of cuboid are as follow: ##### Question 8:

Three cubes each with 2 cm edge are placed side by side to form a cuboid. Sketch an oblique or isometric sketch of this cuboid. ##### Question 9:

Try to guess the number of cubes in the following arrangements (Fig.) : Number of cubes in the arrangements are as follows:
(i) 24 cubes (ii) 8 cubes
(iii) 9 cubes.

##### Question 10: Numbers on the opposite face:
(a) 5 + 6 is 2 + 1
and (b) 4 + 3 is 3 + 4.

##### Question 11:

What cross-sections do you get when you give a
(i) vertical cut
(ii) horizontal cut
to the following solids?
(a) A brick
(b) A round apple
(c) A die
(d) A circular pipe
(e) An ice cream cone.

When we give a vertical cut then following cross-sections are obtained:
(a) A brick — Cuboid
(b) A round apple — Circular
(c) A die — Square
(d) A circular pipe — Circular
(e) An ice cream cone — Curved shape
When we give a horizontal cut then following cross-sections are obtained:
(a) A brick —Cuboid
(b) A round apple —Circular
(c) A die —Cuboid
(d) A circular pipe —Hemispherical
(e) An ice cream cone —Frustrum

##### Question 12:

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.)  ##### Question 13:

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 !) Shadows of some 3-D objects, when seen under the lamp of an overhead projector. ##### Question 14:

The cube can cast a shadow in the shape of a rectangle.

1. TRUE
2. FALSE

TRUE

##### Question 15:

The cube can cast a shadow in the shape of a hexagon.

1. TRUE
2. FALSE

FALSE

##### Question 16:

For each solid, the three views (1), (2), (3) are given. Identify for each solid the corresponding top, front and side views. (1) Front (2) Side (3) Top

##### Question 17:

For each solid, the three views (1), (2), (3) are given. Identify for each solid the corresponding top, front and side views. (1) Top (2) Side (3) Front

##### Question 18:

For each solid, the three views (1), (2), (3) are given. Identify for each solid the corresponding top, front and side views. (1) Side (2) Front (3) Top

##### Question 19:

For each solid, the three views (1), (2), (3) are given. Identify for each solid the corresponding top, front and side views.   