SOLUTION: What is the circumference of a circle if the area of the circle is 64? My homework gives me 5 choices. 1) 8 2) 16 3) 8 divided by the square root of pie 4)16 times the square r

Algebra ->  Circles -> SOLUTION: What is the circumference of a circle if the area of the circle is 64? My homework gives me 5 choices. 1) 8 2) 16 3) 8 divided by the square root of pie 4)16 times the square r      Log On


   

Question 16753: What is the circumference of a circle if the area of the circle is 64? My homework gives me 5 choices.
1) 8
2) 16
3) 8 divided by the square root of pie
4)16 times the square root of pie
5) 32 times pie

Answer by venugopalramana(3286) About Me  (Show Source):
You can put this solution on YOUR website!
area of the circle is 64...formula for area is pie * r^2 ,where as formula for circumference or perimeter is 2*pie*r..hence
area =pie*r^2=64
r^2=64/pie
r=sqrt%2864%2Fpie%29 =8/sqrt%28pie%29
circumference=2*pie*r=2*pie*8/sqrt%28pie%29= 16*sqrt%28pie%29 ...hence
16 times the square root of pie is the answer.