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put this solution on YOUR website!The length of a side of a square given the area is given by the square root of the area. So this square has a side length of
The diagonal of any square forms an isoceles right triangle with two of the sides of the square, and the three sides of this triangle are in proportion

:

:

(verify this yourself by considering an isoceles right triangle with legs that measure 1 unit, then applying the Pythagorean Theorem). Knowing that, all we need to do is multiply the side length times

, in this case:

cm is the length of the diagonal of a square with an area of

.