# NCERT Book Class 9th Maths Chapter 11 Surface Areas And Volumes PDF Download

Class 9th Maths Chapter 11 – Download NCERT Book Surface Areas And Volumes Class 9th PDF to your device directly without any ads or redirect.

PDF Name Surface Areas And Volumes – NCERT Book Class 9th Maths Chapter 11 14 1.5 MB English PDF PREVIEW

## Introduction to Class 9th Maths Chapter 11

The Class 9th Maths Chapter 11 is about surface areas and volumes. It covers the surface area of a right circular cone, as well as the surface areas and volumes of other shapes such as cubes, cuboids, cylinders, spheres, hemispheres, pyramids, and prisms.

The chapter provides formulas for calculating the surface area and volume of each shape, and includes examples to help illustrate the concepts. Overall, Surface Areas And Volumes class 9 PDF aims to help readers understand the properties of these shapes and how to calculate their surface areas and volumes.

## What will you learn from this chapter?

In this Class 9th Maths Chapter 11, you will learn about surface areas and volumes of different shapes such as cubes, cuboids, cylinders, spheres, hemispheres, pyramids, and prisms. You will learn how to calculate the surface area and volume of each shape using specific formulas.

The chapter includes examples and activities to help you understand the concepts and apply them in real-life situations. By the end of the chapter, you should have a good understanding of the properties of these shapes and how to calculate their surface areas and volumes.

### What is the difference between surface area and volume?

Surface area is the total area that the surface of an object occupies, while volume is the amount of space that an object takes up.

### What is the formula for finding the surface area of a cylinder?

The formula for finding the surface area of a cylinder is 2πr² + 2πrh, where r is the radius of the base and h is the height of the cylinder. The first term, 2πr², represents the area of the two circular bases of the cylinder, while the second term, 2πrh, represents the area of the curved surface of the cylinder. To find the total surface area of the cylinder, you add these two terms together. This formula is useful in real-world applications, such as calculating the amount of paint needed to cover a cylindrical object.

### How do you calculate the volume of a sphere?

To calculate the volume of a sphere, you can use the formula (4/3)πr³, where r is the radius of the sphere. First, measure the radius of the sphere. Then, cube the radius and multiply it by 4/3 and π. This will give you the volume of the sphere in cubic units. The formula is derived from the fact that the volume of a sphere is equal to four-thirds of the product of π and the cube of its radius.

### What is the surface area of a cube with a side length of 5 cm?

The surface area of a cube with a side length of 5 cm is 150 square cm.

### How do you find the slant height of a cone?

The slant height of a cone can be found using the Pythagorean theorem, which states that the square of the slant height is equal to the sum of the square of the radius and the square of the height.

### What is the difference between a pyramid and a prism?

A pyramid has a base that is a polygon, while a prism has a base that is a rectangle or a square.

### How do you calculate the volume of a triangular prism?

The volume of a triangular prism can be calculated by multiplying the area of the base by the height of the prism.

### What is the formula for finding the surface area of a hemisphere?

The formula for finding the surface area of a hemisphere is 3πr², where r is the radius of the hemisphere. This formula only takes into account the curved surface area of the hemisphere, as it is half of a sphere. If you want to find the total surface area of the hemisphere, you can use the formula 3πr², which includes the curved surface area and the area of the circular base of the hemisphere.

### How do you calculate the volume of a cone?

To calculate the volume of a cone, you can use the formula (1/3)πr²h, where r is the radius of the base of the cone and h is the height of the cone.

### How can you use the concept of surface area to calculate the amount of paint needed to cover a cylinder-shaped object?

To calculate the amount of paint needed to cover a cylinder-shaped object, you can use the formula for the surface area of a cylinder and then divide by the coverage area of the paint.