Answer: The length of one side is 9m.
Explanation:
If area is 81 square meters, that means A = 81 m^2.
Since A = s^2, we can substitute s^2 for A. Then
(s^2) = 81 m^2
Take the square root of both sides to solve for s:
(s^2)^(1/2) = (81 m^2)^(1/2)
s = 9 m