How many square feet does one yard of concrete cover at a thickness of 4 inches?

To determine how many square feet one yard of concrete covers at a thickness of 4 inches, it's essential to understand the conversion between cubic yards and square feet, along with the thickness measurement.

One cubic yard of concrete is equivalent to 27 cubic feet (since a yard measures 3 feet in each dimension: 3 ft × 3 ft × 3 ft = 27 cubic feet). If you're pouring concrete at a thickness of 4 inches, you need to convert that thickness into feet. There are 12 inches in a foot, so 4 inches converts to approximately 0.33 feet (4 inches ÷ 12 inches/foot = 0.33 feet).

To find the area that one cubic yard of concrete at 4 inches thick will cover, you can divide the total volume in cubic feet by the thickness in feet:

27 cubic feet ÷ 0.33 feet = approximately 81.82 square feet.

This rounds down to about 80 square feet, which is why the correct answer in this context is recognized as 80 square feet. This understanding not only demonstrates the volume-to-area conversion but also reinforces the importance of unit conversions in practical scenarios like calculating the coverage of concrete.