The equation $\displaystyle{C}={2}\pi{r}\usepackage{cmbright}\Huge\$ is the formula that relates the circumference of a circle to the radius. This gives us the ability to calculate pi if we physically measure a circle's circumference and radius. Solve the equation for $\displaystyle\pi\usepackage{cmbright}\Huge\$ to get the formula you would use to perform this activity.