NCERT Solutions for Class 9 Maths Exercise 13.8 Surface Areas and Volumes in Hindi and English medium updated for new academic session 2022-2023. Exercise 13.8 solutions is updated for CBSE and State board students as per new NCERT Book. Get the solutions in PDF and Videos format to download for offline use.

## NCERT Solutions for Class 9 Maths Exercise 13.8

### Volume of a Sphere in Exercise 13.8

So far, we know that just like the circle which a two-dimensional figure is, a sphere is a 3-dimensional object. Every aspect of the object sphere can be defined mathematically. Till now we have understood how to calculate the curved surface area of sphere.

Now we will study to calculate the volume of the sphere. Since all the 3-dimensional objects consist of the one major factor that they occupies space means have volume. In class 9 Maths exercise 13.8, we will practice the different ways to calculate volume of sphere.

#### Ways to find the Volume of Sphere in Exercise 13.8

The volume of the object is to have the space to carry any substance inside. In the matter like sphere and hemisphere, the number of cubic units are that will fill a hollow thin sphere.

The hollow thin structure storage of the sphere or hemisphere is known as the volume of the Sphere or hemisphere. In Exercise 13.8, questions are based on volumes of sphere and hemi-sphere. Using just the value of radius or diameter, we can easily find it. To get to the answer we can take radius value into account that a sphere has.

##### Solutions of Exercise 13.8 in Class 9 Maths

The formula for volume of a sphere is 4/3 πr³. If radius or diameter of sphere is given, use the direct formula to find the volume of sphere. In some questions, the surface area of the sphere is given and we have to find the volume. In that case, find the radius first, using formula of surface area and then use this value of radius in formula of finding volume.

###### Volume of a Hemi-sphere

Since we have already learn the formula of Sphere, now it is easy to find its volume. This makes the explanation of hemisphere exponentially short which gives the formula 2/3 πr3.

This is because we know the hemisphere is the half of the full sphere. This is the logical answer of why the formula looks like that. Here is the thing to know the volume of a sphere is measured in cubic units. i.e. m³ and cm³.