Correct. In our right triangle, $\displaystyle{a}={3}\usepackage{cmbright}\Huge\$ and $\displaystyle{b}={6}\usepackage{cmbright}\Huge\$ . By the Pythagorean Theorem, $\displaystyle{{c}}^{{2}}={{a}}^{{2}}+{{b}}^{{2}}={{3}}^{{2}}+{{6}}^{{2}}={9}+{36}={45}\usepackage{cmbright}\Huge\$ , so $\displaystyle{c}=\sqrt{{{45}}}\usepackage{cmbright}\Huge\$ .