In this formula, r is the radius of the circle at the base of the cone and h is the height of the cone. The image below shows what we mean by the radius and height:
"Find the Volume" Widget
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Follow the instructions in the bottom-left corner.
On the last click, the formula, workings, and answer will appear in the yellow box.
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How to Find the Volume of a Cone
Question
What is the volume of a cone with a circular base with a radius of 5 cm and a height of 10 cm, as shown below?
Step-by-Step:
1
Start with the formula:
Volume = πr2h ⁄ 3
Don't forget: π is pi (≈ 3.14) and r2 = r × r (r squared) and ⁄ means ÷.
2
Substitute the radius and the height into the formula. In our example, r = 5 and h = 10.
Volume = π × 52 × 10 ⁄ 3
Volume = π × 5 × 5 × 10 ÷ 3
Volume = π × 250 ÷ 3
Volume = 3.14 × 250 ÷ 3
Volume = 262 cm3
Answer:
The volume of the cone with a circular base with a radius of 5 cm and a height of 10 cm is 262 cm3.
Lesson Slides
The slider below shows another real example of how to find the volume of a cone.
What Is a Cone?
A cone is an object which starts with a circle, and then tapers to a point.
A Cone in a Cylinder
If a cone is placed in a cylinder, the volume of the cone is exactly a third of the volume of the cylinder.
Can you work out why?