In algebra, an equation is always formed by at least two variables: the dependent and independent. The independent variable are the ones you manipulate, or the ones you could directly measure. In this case, the independent variable is the side length. The dependent variable is the one that changes with the independent variable - which is the area. The equation for the area of the square is:
A = s^2, where s is the side length of the square
So, when the area does not exceed 100 m^2, then the upper limit is 100. Thus, the maximum side should be
100 > s^2
s < 10 m
The range is the coverage of the dependent variable. With that being said, the range is therefore from 0 to 100 square meters. Negative values are impossible so the lower limit is 0.
