# NCERT Solutions for Class 7 Maths Chapter 15 Exercise 15.3

NCERT Solutions for Class 7 Maths Chapter 15 Exercise 15.3 (Ex. 15.3) Visualising Solid Shapes in PDF file format free to use updated for 2021-2022. All the contents are based on latest NCERT Books issued for academic session 2021-22.

Class 7 math exercise 15.3 is based on vertical and horizontal cross section of solid objects. In exercise 15.3, there is only one question is given, which quite easy to understand by observing only.## Class 7 Maths Chapter 15 Exercise 15.3 Solution

### CBSE NCERT Class 7 Maths Chapter 15 Exercise 15.3 Solution in Hindi and English Medium

Class: 7 | Mathematics |

Chapter: 15 | Visualising Solid Shapes |

Exercise: 15.3 | PDF and Videos Solution |

### Class 7 Maths Chapter 15 Exercise 15.3 Solution in Videos

#### Sphere

An object which is in the shape of a ball is said to have the shape of a sphere.

##### Parts of a Sphere

(i) A sphere has no vertex.

(ii) A sphere has no edge.

(iii) A sphere has a curved surface.

### Class 7 Maths Exercise 15.3 Extra Questions

##### What is special about a sphere?

Important Facts: A sphere is a symmetrical object. All the surface points of sphere are at equidistant from center. A sphere has only curved surface, no flat surface, no edges and no vertices.

##### Why is a sphere the most efficient shape?

A sphere has the lowest possible surface area required to bound any given volume. Therefore, it is the most energy-efficient configuration.

##### How many faces edges and vertices has a triangular pyramid?

Properties of Triangular Pyramid

It has 4 faces. The 3 side faces are triangles. The base is also a triangle. It has 4 vertices (corner points).

##### Triangular Pyramid

A triangular pyramid is a pyramid having a triangular base. The tetrahedron is a triangular pyramid having congruent equilateral triangles for each of its faces.

##### Properties of Triangular Pyramid

A triangular pyramid has:

(i) A triangular pyramid has 4 vertices.

(ii) A triangular pyramid has 4 edge.

(iii) A triangular pyramid has 6 surface.

### Class 7 Maths Exercise 15.3 Important Questions

##### What do you call a pyramid with a triangle base?

A triangular pyramid is a pyramid having a triangular base. The tetrahedron is a triangular pyramid having congruent equilateral triangles for each of its faces. The regular tetrahedron is a special case of the triangular pyramid.

##### How many triangles are in a triangular pyramid?

A lower symmetry case of the triangular pyramid is C3v, which has an equilateral triangle base, and 3 identical isosceles triangle sides.

##### Why is a pyramid a triangle?

A triangle is formed by each pyramid’s side (every base edge and the apex). There are four triangular sides of a triangle-based pyramid. This means the pyramid’s three sides are the same size as each other, and if you rotate it, the pyramid looks the same.