The perimeter of any square is 4s, where s is the side length of the square. Here, each of the sides is equal to 8 side lengths of the smaller squares. If we use s to describe the side length of the small squares, then the side length of the checkerboard is 8s and its perimeter is 4 x 8s = 32s.
So, what is s? We're given the area of the small squares - 14 cm² - but how do we get the side length from that? Well, remember that, to find the area of a square, we (pretty naturally) square its sides. So, if these small squares have side lengths of s, then we know that s² = 14. On the other hand, if we want to find the side length, we need to take the square root of the area. So, s = √14.
Going back to our checkerboard, we can now say that our perimeter is equal to exactly 32√14 cm², which is approximately 119.7 cm²
