the perimeter of the square should be 48 square feet.
we know that in a square, all the sides are the same length. the square root of 144 is 12, and we know the square root of a number (12) is what gives the square root (144) when multiplied by itself. the formula of area (in a square) is A = bh, where the b stands for base and the h stands for height. if the base and height multiplied equals 144, we know both the base and height are 12 square feet. so now that we know all of the sides are 12 square feet, we can finally solve perimeter. you find perimeter by adding up all the sides. 12 + 12 + 12 + 12 = 48. (you can also do 12 x 4). this is how we know the perimeter is 48 square feet.
^^ only included this in case you needed to give an explanation.