We have the following equation of the area of a square:
[tex]A=s^2[/tex]where s is the length of the side.
In this case, we have that the area is 36 square meters, then:
[tex]\begin{gathered} A=36m^2=s^2 \\ \Rightarrow s^2=36 \end{gathered}[/tex]if we apply the square root on both sides we get:
[tex]\begin{gathered} \sqrt[]{s^2}=\sqrt[]{36}=6 \\ \Rightarrow s=6 \end{gathered}[/tex]therefore, the measure of the side of the square is 6 meters