FAN AND MEDAL
A cylindrical well is 20 meters deep and has a diameter of 1.5 meters. Approximately how many cubic meters of soil were dug out to make the well? (Use π = 3.14.)

11.78 cubic meters
35.33 cubic meters
121.20 cubic meters
141.30 cubic meters

Question

FAN AND MEDAL
A cylindrical well is 20 meters deep and has a diameter of 1.5 meters. Approximately how many cubic meters of soil were dug out to make the well? (Use π = 3.14.)

 11.78 cubic meters
 35.33 cubic meters
 121.20 cubic meters
 141.30 cubic meters

mathstudent55 · Answer

You need to find the volume of a cylinder.
Do you know the formula of the volume of a cylinder?

anonymous · Answer

not really i am not very good at math

mathstudent55 · Answer

The formula is:

$\Large V_{cylinder} = \pi r^2 h$

$\pi$ is approximately 3.14
r is the radius of the base
h is the height of the cylinder

mathstudent55 · Answer

You were given the diameter of the base, 1.5 m.
You need the radius of the base.
The radius is half of the diameter.
First, find the radius.
Then multiply the radius by itself to find r^2.
Then multiply that by pi and by the height.
That will give you the volume.
Try it and tell me what you get.

anonymous · Answer

thank you