what is the formula of diagonal of square

To find the diagonal of a square, you can use the formula d = a√2, where d is the diagonal length and a is the side length of the square. This formula is derived from the Pythagorean theorem, which states that the square of the hypotenuse of a right triangle is equal to the sum of the squares of the other two sides. In the case of a square, the two sides are equal, so the formula simplifies to d = a√2.