Question

If a circle has circumference c, what is it’s are in terms of C

Answer 1

$\text {Circumference = } 2 \pi r$

$c = 2 \pi r$

$\text {r = } \dfrac{c}{2 \pi }$


$\text {area = } \pi r^2$

Sub r into area:

$\text {area = } \pi ( \dfrac{c}{2 \pi } )^2$

$\text {area = } \dfrac{\pi c^2}{4 \pi^2 }$

$\text {area = } \dfrac{\ c^2}{4 \pi }$