What volume in cubic feet is needed to backfill a trench measuring 6x6x6 feet?

To determine the volume needed to backfill a trench that measures 6 feet in length, 6 feet in width, and 6 feet in depth, you can use the formula for calculating the volume of a rectangular prism, which is:

Volume = Length × Width × Depth.

In this case, you would substitute the dimensions of the trench into the formula:

Volume = 6 ft × 6 ft × 6 ft = 216 ft³.

Thus, the volume of 216 cubic feet represents the total space that the trench occupies, and hence, the amount of material needed to backfill it is also 216 cubic feet. This makes it the correct answer, as it accurately reflects the total volume of the trench that must be filled.