What is the maximum number of square inches in the area of a rectangle with a perimeter of 12 inches?
I know that the area of a rectangle is length times width, and that the perimeter is the sum of the lengths of all four sides. I also know that for a fixed perimeter, the rectangle with the largest area is a square. So, I want to find the length of the side of a square that has a perimeter of 12 inches. I can divide 12 by 4 to get the length of one side, which is 3 inches. Then, the area of the square is 3 times 3, which is 9 square inches. 