Correct. The formula for the area of a triangle is $\displaystyle{A}={\left(\frac{{1}}{{2}}\right)}{b}\cdot{h}\usepackage{cmbright}\Huge\$

Substitute the values $\displaystyle{b}={12}\usepackage{cmbright}\Huge\$ and $\displaystyle{h}={3}\usepackage{cmbright}\Huge\$ :

$\displaystyle{A}={\left(\frac{{1}}{{2}}\right)}{12}\cdot{3}={\left(\frac{{1}}{{2}}\right)}{36}={18}\usepackage{cmbright}\Huge\$

The area of the triangle is 18 square yards.