Question 869599
For a circle,
{{{C=2*pi*R}}}
and
{{{A=pi*R^2}}}
so,
{{{R=C/(2pi)}}}
{{{A=pi*(C/(2pi))^2}}}
{{{A=pi*(C^2/(4pi^2))}}}
{{{A=C^2/(4pi)}}}
You can plug in the value of {{{C}}} and solve for {{{A}}}.