Learn how to find the area of a square using the diagonal which creates a 45 45 90 triangle. The special rules of a 45 45 90 triangle can be used to find the side length.
I think that the most easiest way in this case is just apply formula (d^2)/2. Where "d" is the diagonal of the square. It is the formula for determining the area of rhombus. More over square is the particular case of rhombus with equal angles and equal diagonals. It is faster and you do not need to determine and calculate the side of the square as you can calculate area directly. (6^6)/2=36/2=18.
Given any unit of measurement, if the two legs of a right triangle are both 1 unit long, according to the Pythagorean theorem, the square constructed on the hypotenuse c must be equal to 1² + 1², that is, 2. It follows that c is equal in this case to the square root of 2. To simply, there is a rule, that says the length of the hypothenuse is: x sq_root2. Where x is the length of the other 2 sides of the isosceles triangle.
