This is when all the sides are the same length. In order to calculate the volume of a box multiply the length times the width times the height of the box. The volume of a rectangular box can be calculated if you know its three dimensions.
Then find the radius of the circle at the top or bottom.
If a cube has side length a then. Just enter the length the width and the height of the box and hit the calculate button. You can then multiply them together to get volume. Please choose your furniture from the list.