Step-by-step explanation:
» The base of a the cylinder is a circle, assume it is a general circle;
[tex]{ \tt{area = \pi {r}^{2} }} \\ { \tt{ = 3.14 \times {( \frac{12}{2}) }^{2} }} \\ \\ = { \tt{3.14 \times {6}^{2} }} \\ = { \tt{3.14 \times 36}} \\ { \tt{ =113.0973355292325 }} \\ = { \boxed{ \blue{ \tt{ \: area =113.10 \: {cm}^{2} }}}}[/tex]