What is the area of a manhole that measures 40 inches in diameter, expressed in square feet?

To find the area of a manhole with a diameter of 40 inches, we first need to convert the diameter into feet, since the answer is required in square feet. There are 12 inches in a foot, so:

40 inches ÷ 12 inches/foot = 3.33 feet (approximately).

The formula for the area of a circle is:

Area = π * r².

Since we have the diameter, we can find the radius by dividing the diameter by 2:

Radius (r) = 40 inches ÷ 2 = 20 inches.

Now, convert the radius into feet:

20 inches ÷ 12 inches/foot = 1.67 feet (approximately).

Now we can calculate the area using the radius:

Area = π * (1.67 feet)² = π * 2.7889 ft² (approximately) ≈ 3.14 * 2.7889 ft² ≈ 8.75 ft² (approximately).

When rounded appropriately, this value aligns closely with the second answer choice of 8.71 ft², indicating it's the most accurate option based on the area calculation for the manhole. Thus, the area of the manhole expressed in