It is given in the question that
The area of a square sandbox is 46 ft.².
Let the length of the side of the square sandbox is x ft .
And formula of area of square is
[tex]Area = side^2[/tex]
Substituting the given value of area
[tex]46 = side^2[/tex]
We need to get rid of square, and for that we take square root on both sides
[tex]\sqrt{46}=side[/tex]
And the formula of perimeter of square is
[tex]Perimeter=4*side[/tex]
[tex]Perimeter=4\sqrt{46}=27ft[/tex]