Which formula would you use to find the volume of a cylinder if you have the radius and height?

To find the volume of a cylinder when you know the radius and the height, you would use the formula V = πr²h. This formula is derived from the relationship between volume and the cross-sectional area and height of the cylinder.

In this formula, πr² represents the area of the circular base of the cylinder, where r is the radius. Since a cylinder is essentially made up of multiple stacked circular bases of the same size, to find the total volume, you multiply the area of the base by the height of the cylinder, which is represented by h. Thus, the volume can be calculated as the area of the base times the height, leading to the formula V = πr²h.

The other options provided do not correctly represent the formula for the volume of a cylinder. For example, using 2πr²h would imply a doubling of the base area, which is not applicable for a standard cylinder. Similarly, πhr and πr(h + r) do not incorporate the correct relationship between the base area and the height needed to determine the volume accurately. Hence, the formula V = πr²h is the correct one to use in this case.