Correct. The formula for the volume of a cone is $\displaystyle{V}=\frac{{1}}{{3}}\pi{{r}}^{{2}}{h}\usepackage{cmbright}\Huge\$ .

Substitute $\displaystyle{r}={3}\usepackage{cmbright}\Huge\$ and $\displaystyle{h}={7}\usepackage{cmbright}\Huge\$ into the formula:

$\displaystyle{V}=\frac{{1}}{{3}}\pi{{\left({3}\right)}}^{{{2}}}\cdot{7}=\frac{{1}}{{3}}\pi\cdot{9}\cdot{7}=\frac{{1}}{{3}}\pi\cdot{63}={21}\pi\usepackage{cmbright}\Huge\$

$\displaystyle{V}\approx{21}\cdot\frac{{22}}{{7}}={66}\usepackage{cmbright}\Huge\$ cubic millimeters