To find the answer, we can use the Pythagoras theorem, where:
[tex]\sqrt{a^{2}+ b^{2} } =c^{2}[/tex]
Where a and b is the side length and c is the diagonal.
In this case:
[tex]\sqrt{56^{2} +56^{2} }
\\ =\sqrt{6272} \\ =79.19596... \\ =79.2(correct to 3 sig. fig.)[/tex]
Therefore, the answer is 79.2cm
Hope it helps!
