6.Find the length of the side of a square whose area is $$441 m^2$$
So we have, Area of the square = $$(side)^2 = x^2\; m^2$$
$$x^2 = 441$$
$$\qquad \begin{array}{c|lcr} &21\\ \hline 2 &\;\; \;\bar{4}\bar{41}\\ &-4\\ \hline 41 &\;\;\; 41\\ &\;\;\;41\\ \hline &\;\;\;0\\ \hline \end{array}$$
$$\Rightarrow x =\sqrt{441} = 21$$