What is the net area of a wall that is 8' tall and 20' long with a 20 ft² door and four 10.5 ft² windows?

To determine the net area of the wall, you first need to calculate the total square footage of the wall itself and then subtract the areas of any openings, such as doors and windows.

1. Calculate the total area of the wall:

• The wall is 8 feet tall and 20 feet long, so the total area is:

[

\text{Total Area} = \text{Height} \times \text{Length} = 8 , \text{ft} \times 20 , \text{ft} = 160 , \text{ft}².

]

2. Calculate the total area of the openings:

• The door has an area of 20 ft², and there are four windows that each have an area of 10.5 ft². So, the total area of the windows is:

[

\text{Total Area of Windows} = 4 \times 10.5 , \text{ft}² = 42 , \text{ft}².

]

• Now add the area of the door to the total area of the windows:

[

\text{Total Openings}