So to find the volume of a rectangular prism, do L * W * H for the volume. The length of the tissue box is 8, the width is 3 and the height is also 3. With this, plug these together into the equation for the volume.
8 * 3 * 3
24 * 3
72 in^3
It is cubed (^3) , since it is about finding how much space there is in a 3D object. When it is a 2D object such as a rectangle, it is instead squared (^2).
