The plastic lid of a cylindrical container is a circle. The lid has a radius of 9centimeters. What is the circumference of the lid?

We are asked to determine the circumference of a 9 cm radius circle. To do that we will use the following formula:[tex]S=2\pi r[/tex]Where:[tex]\begin{gathered} S=\text{ circumference} \\ r=\text{ radius} \end{gathered}[/tex]Now, we substitute the value of the radius:[tex]S=2\pi(9cm)[/tex]Solving the operations:[tex]S=18\pi=56.55cm[/tex]Therefore, the circumference is 56.55 cm.