to make it easier, aprox pi=3.14
area=pir^2
36=area
36=pir^2
divide both sides by pi
36/pi=r^2
36/3.14=r^2
11.464=r^2
square root both sides
3.39=r
circumfernce=2pir
r=3.39
circumfrence=2pi times 3.39
circumference=pi times 6.78
circumference=3.14 times 6.78
circumfernce=21.29
answer is
circumference=21.29 in
