Correct. To find the radius, you substitute $\displaystyle{16}\pi{{y}}^{{2}}\usepackage{cmbright}\Huge\$ in for the area. If we use $\displaystyle{4}{y}\usepackage{cmbright}\Huge\$ as the radius in our equation for area, we find that $\displaystyle{A}=\pi{{r}}^{{2}}={{\left({4}{y}\right)}}^{{2}}={16}\pi{{y}}^{{2}}\usepackage{cmbright}\Huge\$ .