A slice of cheese is cut from a wheel of parmesan, and the wedge approximate the shape of a rectangular pyramid. It's base is 4 cm wide and 9 cm long. The wedge is 21 cm tall. What is the volume of the piece of cheese?

To find the volume of the piece of cheese, we need to first find the volume of the rectangular pyramid.

The formula for the volume of a rectangular pyramid is:

V = (1/3) * base area * height

First, let's find the base area of the rectangular pyramid:

Base area = length * width
Base area = 9 cm * 4 cm
Base area = 36 cm²

Now, we can plug the values into the volume formula:

V = (1/3) * 36 cm² * 21 cm
V = (1/3) * 756 cm³
V = 252 cm³

Therefore, the volume of the piece of cheese is 252 cm³.