Which expression represents the surface area of a cylinder?

Which expression represents the surface area of a cylinder?

• A. Surface area of a cylinder
• B. Area of a circle
• C. Volume of a cylinder
• D. Surface area of a sphere

Answer: (A)

When you talk about the surface area, you’re looking for the total outside area of a solid. For a cylinder, that includes the two circular ends and the curved side that wraps around. The expression for that total area is SA = 2πr^2 + 2πrh, with r as the radius and h as the height. Among the options, the one that represents the quantity we’re calculating is the surface area of a cylinder, since it names the exact measure being sought. The other choices refer to the area of just one base (a circle), the volume (which is a different property involving how much space is inside), or the surface area of a sphere (a different shape’s formula).

When you talk about the surface area, you’re looking for the total outside area of a solid. For a cylinder, that includes the two circular ends and the curved side that wraps around. The expression for that total area is SA = 2πr^2 + 2πrh, with r as the radius and h as the height. Among the options, the one that represents the quantity we’re calculating is the surface area of a cylinder, since it names the exact measure being sought. The other choices refer to the area of just one base (a circle), the volume (which is a different property involving how much space is inside), or the surface area of a sphere (a different shape’s formula).