Note that the area of a square is: A = s² (s being side). Also note that all the sides of the square are congruent and have the same measurement.
Plug in 37 for A
37 = s²
Isolate the s. Note the equal sign. What you do to one side, you do to the other. Root both sides
√37 = √s²
s = √37
Change the root to a decimal
s = √37 = ~6.1 (rounded to the nearest tenth)
6.1 in is your answer
hope this helps