Answer:
Option B. [tex]12\ ft[/tex]
Step-by-step explanation:
we know that
The area of a square is equal to
[tex]A=x^{2}[/tex]
where
x is the length side of the square
In this problem we have
[tex]A=144\ ft^{2}[/tex]
substitute and solve for x
[tex]144=x^{2}[/tex]
suqre root both sides
[tex]x=12\ ft[/tex]
