Calculate the circle circumference's upper bound if the area is 400cm(square)

Answer 1

πr^2 = 400
r^2 = 400/π
r = 20/(√π)

circumf = 2πr = 2π(20/√π
= 40√π = appr 70.9
change to whatever you mean by upper bound

Answer 2

Like im not sure is this correct (2pi(n-0.5))

Answer 3

how do you calculate the circumfrance in upper bound

Answer 4

If area is less than 400, then the
radius is less than 20/√π
so, the circumference is less than 40√π