The perimeter of a square can be found using the following formula:
[tex]P=4s[/tex]Where "s" is the length of any side of the square.
Then, an expression that represents the perimeter of a square can be:
[tex]4s[/tex]You know that it must be greater that 90 inches be less than 108 inches. Then, using this information, you can set up that:
[tex]90<4s<108[/tex]Now, in order to find the range of possible side lengths asked in the exercise, you need to divide 90 and 108 by 4, as you can see below:
[tex]\begin{gathered} \frac{90}{4}Therefore, the answer expressed in Interval notation, is:[tex](22.5,27)[/tex]