We know that the perimeter is the all the sides added up together. Generally, you have [tex]p = 2l+2w[/tex], where l is length and w is width.
For a square, all sides are of the same length, so you can write [tex]p=4x[/tex], where x is any side.
If the smallest perimeter is 14, then [tex]14 = 4x[/tex], so x is 3.5. If the largest perimeter is 72, then [tex]72 = 4x[/tex], so x is 18.
Therefore, you have 3.5 ≤ x ≤ 18.
