Volume of a cone
The question
A cone marked 3 cm, 2 cm tall
How it works.
base × height
base:3.14 × 3 × 3 =28.26
base:28.26
28.26 × 2 =56.52
cylinder:56.52
3 cones fill 1 cylinder
56.52 ÷ 3 =18.84 cubic cm
- 01
Same idea as a box: the area of the base times how tall it is. Here the base is a circle.
- 02
The circle's area is π × r × r = 3.14 × 3 × 3 = 28.26 square cm.
- 03
Times the height: 28.26 × 2 = 56.52 cubic cm. That is the cylinder around the cone.
- 04
A cone is exactly one third of that cylinder, so divide by 3: 56.52 ÷ 3 = 18.84 cubic cm.