In the cylinder surface area expression, which term represents the circular ends?

In the cylinder surface area expression, which term represents the circular ends?

• A. 2πr^2
• B. πdh
• C. 2πrh
• D. πd^2

Answer: (A)

The circular ends contribute twice the area of a circle. Each end has area πr^2, and there are two ends, so together they add 2πr^2 to the surface area. In the cylinder’s total surface area, this term sits with the lateral (curved) surface area, giving SA = 2πr^2 + 2πrh. So the term that represents the circular ends is 2πr^2. πdh is another way to express the same lateral area when using diameter, and 2πrh is the lateral surface area. πd^2 does not represent the ends; it does not match the end area, so it’s not correct for the circular ends.

The circular ends contribute twice the area of a circle. Each end has area πr^2, and there are two ends, so together they add 2πr^2 to the surface area. In the cylinder’s total surface area, this term sits with the lateral (curved) surface area, giving SA = 2πr^2 + 2πrh. So the term that represents the circular ends is 2πr^2.

πdh is another way to express the same lateral area when using diameter, and 2πrh is the lateral surface area. πd^2 does not represent the ends; it does not match the end area, so it’s not correct for the circular ends.