It looks like you're working with a formula related to the surface area of a cylinder. The equation $A = 2\pi rh$ represents the lateral surface area of a cylinder, where:

• $A$ is the lateral surface area.
• $r$ is the radius of the base of the cylinder.
• $h$ is the height of the cylinder.
• $\pi$ is the mathematical constant approximately equal to 3.14159.

So, the formula $A = 2\pi rh$ calculates the lateral surface area of the cylinder, which is the area of the side surface excluding the top and bottom circles.

Would you like more details or have any questions?

Here are 5 related questions to expand on this concept:

1. How do you calculate the total surface area of a cylinder?
2. What is the formula for the volume of a cylinder?
3. How would the formula change if you were working with a cone instead of a cylinder?
4. What happens to the surface area if the radius is doubled but the height remains the same?
5. Can you derive the formula for the lateral surface area of a cylinder from basic principles?

Tip: When dealing with problems involving $\pi$, consider whether an exact answer (in terms of $\pi$) or a decimal approximation is required.