Question

multiple choice (single)
find the volume of the following cone.
a 18π cm³
b 24π cm³
c 30π cm³
d 72π cm³

Explanation:

Step1: Find the radius

The diameter is 6 cm, so the radius $r=\frac{6}{2}=3$ cm.

Step2: Recall the volume formula of a cone

The volume formula of a cone is $V = \frac{1}{3}\pi r^{2}h$.

Step3: Substitute values into the formula

Here, $r = 3$ cm and $h=8$ cm. So $V=\frac{1}{3}\pi\times3^{2}\times8$.
First calculate $3^{2}=9$, then $\frac{1}{3}\times9\times8\pi$. $\frac{1}{3}\times9 = 3$, and $3\times8\pi=24\pi$ $cm^{3}$.

Answer:

B. $24\pi$ $cm^{3}$