[tex]U=\pi (r+h) \\\\ 16 \frac{1}{2}= \frac{22}{7}\cdot (r+2) \\\\ \frac{33}{2} : \frac{22}{7}=r+2 \\\\ \frac{\not 33}{2}\cdot \frac{7}{\not 22}=r+2 \\\\ \frac{3}{2} \cdot \frac{7}{2}=r+2 \\\\ \frac{21}{4}=r^{(4}+2^{(4} \\\\ 21=4r+8 \\\\ 4r=21-8 \\\\ 4r=13 \\\\ \boxed{r=\frac{13}{4}}[/tex]
