Question 961931
The area of the square equals side squared, s^2. Therefore, a side equals to the square root of the area:
{{{sqrt(81)= 9}}} That's the length of each side, 9.
If we trace a diagonal across the square, we are in fact dividing the square into 2 triangles, and the diagonal line is the hypotenuse.
Per Pythagoras:
The length of the hypotenuse equals the square root of the sum of the squares of the sides:
{{{sqrt(9^2+9^2)= 12.73}}}
12.73 is the length of the diagonal