Count the little squares, pretending they are each 1 in2 each. You'll find there are 289 of themCount the length of each side. You'll find there are 17 on a side. How do we find it without drawing and counting? Use the formula: Substitute 289 for A Take the square root of both sides: Get your calculator and take the square root of 289. You'll get 17. So So each side of that square is 17 inches long. Edwin