The perimeter of a square with an area of 40,000 is 800. Each side contains a value of 200. 200 X 200 = 40,000 (base X height). Here's why: We know that the area of square is calculated by squaring the length of the side. In other words, A = s2. Therefore, if we know the area, we can calculate the length of each side by finding the square root of the area. In this case, SQRT(40,000) = 200. So, the square in question has four sides with a length of 200. The perimeter of the square is the sum of the lengths of the sides. For a square, P = 4s, which is 4 x 200 = 800.