Question 675414
P = 4s


18 <= P <= 64


18 <= 4s <= 64


18/4 <= s <= 64/4


4.5 <= s <= 16


So if the perimeter of a square is to be between 18 and 64 feet, inclusively, then the side lengths of the square are between <font color="red">4.5 feet</font> and <font color="red">16 feet</font>, inclusively.