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## Class 10 (Old)

### Course: Class 10 (Old)>Unit 12

Lesson 3: Frustum of a cone

# Volume of a frustum

Let's learn how to find the volume of a frustum by looking at an example problem. Let's use an intuitive approach to find the volume rather than directly applying the formula. Created by Aanand Srinivas.

## Want to join the conversation?

• This concept is just frustrumating.
• Why did he multiply 1/3 by 22/7 and not pi?
• He did not want the answer in terms of pi, and 22/7 is a close approximation
• I didn`t get the idea of finding h1 and h2
• it's important to find the height of the two cones in order to calculate the volume of the cones and thus, that of the frustom.

This is if you are following the method in this video. it wont be necessary if you use the formula for a frustom's volume which is-
1/3πh(r1^2 + r2^2 + r1*r2)
over here- h is the height provided- in this case- 4 cm
and r1 and r2 are the two radii provided.

i personally find this way of solving faster and easier, instead of finding the two heights and then subtracting the two volumes.