Answer: 6 inches.
Step-by-step explanation: The piece of glass is a square and thus has equal sides. The area is 36 inches^2. We can call the unknown value (the side length) x. x^2 is equal to 36, because area is length*width and length and width are the same in a square. Thus, x = 6 and the side length of the piece of glass is 6 inches.
