This table describing the steps for finding the formula for the surface area of a cylinder is partially filled in.

Question

Step and Description Formulas
1. Area of one circular base of the cylinder 1.
2. Combined area for both top/bottom circles 2.
3. Area of curved surface that unrolls to a rectangle with height, h, and base equivalent to the cylinder's circumference 3.
4. Sum of the areas of the two circles and the rectangle 4.
5. Simplified surface area formula (factoring out common term) 5.
Which formula corresponds to step 2?

Answer 1

To find the formula corresponding to step 2, we need to calculate the combined area for both the top and bottom circular bases of the cylinder.

1. The area of one circular base of the cylinder is given by the formula:
   \[ A = \pi r^2 \]
   where \( r \) is the radius of the base.

2. Since there are two circular bases (top and bottom) in a cylinder, the combined area for both bases is:
   \[ 2 \times \pi r^2 \]

Therefore, the formula that corresponds to step 2 is:
\[ 2\pi r^2 \]