Incorrect. The dime has a diameter of about 18 millimeters. Divide this value in half to find the radius of the dime: $\displaystyle\frac{{18}}{{2}}={9}\usepackage{cmbright}\Huge\$ millimeters. Use $\displaystyle{r}={9}\usepackage{cmbright}\Huge\$ in the formula $\displaystyle{A}=\pi{{r}}^{{2}}\usepackage{cmbright}\Huge\$ to find the area of one side of the dime.