You can put this solution on YOUR website! A square has 4 equal sides. Let's use x to represent the length of a side.
The perimeter is the distance around the square, and since there are 4 sides, the perimeter of the square would be 4x. Let's set up an equation and solve for x.
80=4x
/4 /4 Division property of equality
20=x
The area of a square is side squared, or x². We know that x=20 so we can substitute and solve for the largest area.
20²=400. Thus the answer is 400 cm squared.