What is the approximate area of a circular roof with a 12-foot radius?

What is the approximate area of a circular roof with a 12-foot radius?

• A. 452 sq ft
• B. 144 sq ft
• C. 113 sq ft
• D. 376 sq ft

Answer: (A)

The area of a circle is found using A = πr^2. With a radius of 12 feet, r^2 is 144, so A = π × 144 = 144π square feet. Using π ≈ 3.1416, 144π ≈ 452.39, which rounds to about 452 square feet. That’s why the best choice is 452 sq ft. The other options reflect common slips: 144 would be what you get if you forgot to multiply by π, 113 corresponds to π × 6^2 (radius 6), and 376 is from a miscalculation involving π and the radius.

The area of a circle is found using A = πr^2. With a radius of 12 feet, r^2 is 144, so A = π × 144 = 144π square feet. Using π ≈ 3.1416, 144π ≈ 452.39, which rounds to about 452 square feet. That’s why the best choice is 452 sq ft. The other options reflect common slips: 144 would be what you get if you forgot to multiply by π, 113 corresponds to π × 6^2 (radius 6), and 376 is from a miscalculation involving π and the radius.