For a duct measuring 10 inches by 20 inches, what is the area in square feet?

To calculate the area of a duct measuring 10 inches by 20 inches, you need to first convert the dimensions from inches to feet. There are 12 inches in a foot, so:

• The width of 10 inches is equivalent to 10 ÷ 12 = 0.833 feet.

• The height of 20 inches is equivalent to 20 ÷ 12 = 1.667 feet.

Next, you can find the area of the duct in square feet by multiplying the width by the height:

Area = Width × Height = 0.833 feet × 1.667 feet.

The product of these two numbers gives:

Area = 1.388 square feet.

Rounding this to two decimal places gives 1.38 square feet, which corresponds to the correct option. This calculation demonstrates how to convert measurements and find the area, which is a crucial skill in HVAC applications where precise duct sizes are necessary for efficient airflow and system performance.