Question

What is the volume of a cone that has a radius of 4 cm and a height of 9 cm?

Use 3.14 to approximate pi and express your answer in hundredths.

______cm^3

Answer 1

150.8cm³ Hope this helps!!!! :)

Answer 2

For any sort of pyramid or cone, the volume is 1/3 of the volume of a prism with the same base and height. Since the volume of a prism/cylinder is
`V=Bh`, the volume of a pyramid/cone is
`V=\frac{1}3Bh`.

In this case, our base is a circle, which has a radius of 4 cm.
The area of a circle is
`A=\pi r^2` where r is the radius.

`A=\pi (4)^2=\pi (4*4)=16\pi=B`

We now know that our base is 16π cm.
We also know that our height is 9 cm.
Let's plug these into our volume formula.


`V=\frac{1}3*16\pi *9`

Use 3.14 to approximate pi as the question states. 16 × 3.14 = 50.24.


`V\approx\frac{1}3*50.24*9`

We could punch all of that into our calculator to get the same answer, but since 1/3 of 9 is clearly 3, let's just go with that.


`V\approx3*50.24`


`\boxed{V\approx150.72\ cm^3}`