Question

Write a formula giving the area of a circle in terms of its circumference

Answer 1

C=2pi*r-----> r=C/2pi
A= pi*r^2
A= pi*(C/2pi)^2

Answer 2

i dont understand that

Answer 3

what part don't you understand?

Answer 4

where did the number 2 come from

Answer 5

the entire 2*pi came from the fact that,the full circle is of 2*pi radians or 360 degrees...