What is the area of a wall that is 10' tall by 40' long?

To calculate the area of a wall, you can use the formula for the area of a rectangle, which is length multiplied by height. In this case, the wall has a height of 10 feet and a length of 40 feet.

When you perform the calculation, you multiply the two dimensions:

Area = Height × Length = 10 ft × 40 ft = 400 ft².

This result shows that the area of the wall is indeed 400 square feet. Understanding this calculation is essential for applications in building analysis, as accurate measurements are crucial for tasks such as estimating materials, assessing energy efficiency, and planning renovations. The other options do not match the results of this calculation, which confirms the accuracy of the answer provided.