Question 282056
Since it is a square, every side is the same.

Which means the side must be 8 because 8 * 8 = 64.

If we draw a diagonal of a square, you will have a triangle, the hypotenuse is:

{{{x^2 + y^2 = z^2}}}

since the sides of the triangle are the same:

{{{8^2 + 8^2 = z^2 = highlight(8 * sqrt(2))}}}