which statement best describes an informal argument for the formula for the volume of a cylinder?

A: a cylinder is a stack of r circles, each with an area of pi r^2 and a thickness of one unit, so its volume formula is V= pir^3

B: a cylinder is a curved lateral surface with area 2pi rh and two circular bases each with area pi r^2, so its volume formula is V=2 pi rh+2 pi r^2

C: a cylinder is a stack of h circles, each with an area of pi r^2 and a thickness of one unit, so its volume formula is V= pi r^2 h.]

D: a cylinder is a curved lateral surface with height h and two circular bases, each with area pi r^2, so its volume formula is V=2 pi r^2 h.

3 answers

The statement that best describes an informal argument for the formula for the volume of a cylinder is:

C: a cylinder is a stack of h circles, each with an area of pi r^2 and a thickness of one unit, so its volume formula is V= pi r^2 h.

This explanation captures the essence of how the volume of a cylinder might be thought of informally as stacking circles (which are the bases of the cylinder) over the height of the cylinder, leading to the formula \( V = \pi r^2 h \).

you sure

Yes, I am confident in my response. Option C provides the most straightforward and intuitive explanation for the volume of a cylinder, by describing it as a stack of circles (the bases) with a specific area (πr²) and extending that area through the height (h) of the cylinder. This aligns well with the mathematical formula \( V = \pi r^2 h \).

To clarify the other options briefly:

  • A: Incorrect because it states the volume as \( V = \pi r^3 \), which is not the correct formula for the volume of a cylinder.
  • B: Incorrect because it combines the lateral surface area and the base areas incorrectly for volume; volume should not include just the lateral surface area.
  • D: Incorrect for the same reason as B; it misrepresents how volume is calculated by including lateral area, and also suggests an incorrect formula.

So, option C remains the best informal argument for deriving the volume of a cylinder.