For a drum 12 ft long and 5 ft in diameter, what is the curved surface area in square inches (area = πDL)?

For a drum 12 ft long and 5 ft in diameter, what is the curved surface area in square inches (area = πDL)?

• A. 27,143
• B. 32,798
• C. 20,000
• D. 25,000

Answer: (A)

A cylinder’s curved surface area is A = π D L, where D is the diameter and L is the length (the height of the drum). For this drum, convert to inches to keep units consistent: diameter 5 ft becomes 60 inches, and length 12 ft becomes 144 inches. Multiply D and L: 60 × 144 = 8640. Multiply by π: 8640 × π ≈ 27,143 square inches. So the curved surface area is about 27,143 in², which matches the given result.