For this case we have that by definition, the area of a square is given by:
[tex]A = L ^ 2[/tex]
Where,
Substituting we have:
[tex]L ^ 2 = 101[/tex]
Then, clearing the side we have:
[tex]L = \sqrt {101}\\L = 10.05 in^2[/tex]
Answer
the approximate side length of a square game board is:
[tex]L = 10.05 in ^ 2[/tex]