I need help with this question please

Answer:
C. 9
Step-by-step explanation:
[tex]area \: of \: square = {side}^{2} \\ \therefore \: {side}^{2} = 81 \\\therefore \: side = \sqrt{81} \\ \therefore \: side = 9 \: feet[/tex]
Hence, side length of square = 9 feet.
Answer:
9 ft
Step-by-step explanation:
Area = 81 ft²
Area of square = length x length
A square has all its sides equal
Therefore
Area = L²
L² = 81 ft²
Find square root of both sides
sq rt L² = sq rt 81 ft²
L = 9 ft
Therefore length of the square = 9 ft
I hope this was helpful, please rate as brainliest