wikiHow Calculating the Diagonal of a Square Calculator To calculate the diagonal of a square, you can use the Pythagorean theorem, which states that the square of the hypotenuse (longest side) of a right triangle is equal to the sum of the squares of the other two sides. In the case of a square, the hypotenuse is the diagonal and the other two sides are the length and width, which are equal. So, if s represents the length of one side of the square, the formula for the diagonal (d) is: d = √(s^2 + s^2) = √2s^2 = s√2 Therefore, the diagonal of a square is equal to the length of one side multiplied by the square root of 2. Example: let's say we have a square with a side length of 8 meters. To calculate the diagonal of this square, we can use the formula: d = s√2 where s is the length of one side of the square. Substituting s = 8 into the formula, we get: d = 8√2 To approximate the value of the diagonal, we can use a calculator to find the square root of 2 and then multiply it by 8: d ≈ 11.31 meters Therefore, the diagonal of the square with a side length of 8 meters is approximately 11.31 meters. Page