The diagonal of a square is 14 m, what is the perimeter

The diagonal of a square is obtained by using Pythagorean theorem. Letting x be the side of the square, 
                                       x² + x² = 14²
Solving x from the equation gives x a value of approximately 9.899 m. The perimeter of a square is four times the length of its side. Thus, the perimeter of the square is approximately 39.60 meters.