Answer:
The side length is 9m
Explanation:
A = 81 m^2
Since the figure is a square, we know the area of a square is A = s^2 where s is the side length
81 m^2 = s^2
Take the square root of each side
sqrt(81 m^2 ) = sqrt( s^2)
9 m = s
The side length is 9m