The cone and cylinder above have the same radius and height. The volume of the cylinder is 69 cm3. What is the volume of the cone?

A.
138 cm3
B.
23 cm3
C.
34.5 cm3
D.
207 cm3

1 answer

The volume of a cylinder is given by the formula:

\[ V_{\text{cylinder}} = \pi r^2 h \]

The volume of a cone is given by the formula:

\[ V_{\text{cone}} = \frac{1}{3} \pi r^2 h \]

Since the cone and cylinder have the same radius \( r \) and height \( h \), we can relate their volumes. Specifically, the volume of the cone is one-third the volume of the cylinder:

\[ V_{\text{cone}} = \frac{1}{3} V_{\text{cylinder}} \]

Given that the volume of the cylinder is 69 cm³, we can substitute this value into the formula for the cone:

\[ V_{\text{cone}} = \frac{1}{3} \times 69 \text{ cm}^3 = 23 \text{ cm}^3 \]

So, the volume of the cone is \( \boxed{23} \text{ cm}^3 \).