Answer
15 inches
Work Step by Step
A square has equal sides, and the area of a square is determined by the formula: $Area=length^{2}$.
In this problem, the area is provided as $225$.
Plug the given area into the formula: $\sqrt 225=\sqrt {length^{2}}$
Simplify: $15= length$.
Therefore, the length of the square is 15 inches.
