Final answer:
The length of one side of a square tile with an area of 58,800 square millimeters is approximately between 242 and 243 millimeters, as derived from the square root of the area.
Step-by-step explanation:
The length of one side of a square wall tile with an area of 58,800 square millimeters lies between the measurements of two numbers, which can be determined by finding the square root of the given area. To find the length of one side, you perform the square root operation because the area of a square is equal to the length of one side squared (side × side).
Upon calculating the square root of 58,800 mm²:

Therefore, the length of each side of the square is approximately 242.489 mm. Since we typically do not use decimal points in millimeters for such measurements, we can say the side length is somewhere between 242 mm and 243 mm.