# NCERT Solutions for Class 7 Maths Chapter 15 Exercise 15.1

NCERT Solutions for Class 7 Maths Chapter 15 Exercise 15.1 (Ex. 15.1) Visualising Solid Shapes updated for new academic session 2021-2022. Practice all questions with the help of PDF, if still any doubt, please visit to videos.

In class 7 math exercise 15.1, we will learn to observe the net of different solids. We will also try to identify the solid using their nets. Questions given in this exercise is mostly based on observation.## Class 7 Maths Chapter 15 Exercise 15.1 Solution

### CBSE NCERT Class 7 Maths Chapter 15 Exercise 15.1 Solution in Hindi and English Medium

Class: 7 | Mathematics |

Chapter: 15 | Visualising Solid Shapes |

Exercise: 15.1 | Hindi and English Medium Solution |

### Class 7 Maths Chapter 15 Exercise 15.1 Solution in Videos

#### Three Dimensional Shapes

three-dimensional shapes (3D shapes) are also called the solids, which have three-dimensions namely length, width and height. 3D shapes can include both polyhedrons and curved solids.

Examples:

Cuboid, Cube, Cylinder, Cone, Sphere and Pyramid etc.

##### One Dimensional Figures

A line segment is one-dimensional, since it has only length.

##### Two Dimensional Figures

The figures which have only length and breadth are called two dimensional (2-D) figures. A 2-D figure does not possess height.

Examples: Square, rectangle, triangle etc.

#### Solids

The objects having definite shape and size are called solids. A solid occupies a fixed amount of space.

Solids occur in various shapes, such as a cuboid, a cube, a cylinder, a cone, a sphere, etc. All solid figures have three elements faces, edges and vertices.

##### Cuboid

A solid bounded by six rectangular faces is called a cuboid. A cuboid has three dimensions, namely length, breadth and height. A matchbox, a chalk box, a brick, a tile, a book, an almirah, etc., are all examples of a cuboid.

##### Properties of Cuboid

(i) A cuboid has 6 rectangular faces. The opposite faces of a cuboid are identical.

(ii) Two adjacent faces of a cuboid meet in a line segment called an edge of the cuboid. A cuboid has 12 edges.

(iii) Three edges of a cuboid meet at a point called a vertex. A cuboid has 8 vertices.

### Class 7 Maths Exercise 15.1 Important Questions

##### What 3D shape has 1 face?

A face is a flat or curved surface on a 3D shape. For examples a cube has six faces, a cylinder has three and a sphere has just one.

##### How are 3D shapes used in everyday life?

We live in a three-dimensional world. Every one of us has height, width, and length. Shapes exist in our 3D world, too: game dice, cuboids, donuts, pyramids, beach balls, traffic cones. All of those are 3D shapes.

##### Does a cone have 1 or 2 faces?

A Face or Surface of a solid figure, can be plane or curved. So, A Cone has TWO faces, one plane face (or surface). And the other one is curved face (or surface) … (1) Plane face is circular in shape.

##### What is the most basic shape?

The square, circle, and triangle are the most basic shapes on Earth, supporting structures both synthetic and natural.