Final answer:
The length of the side of a square with an area of 25² is 25 units. To find this, the square root of the area, which is 625, is taken, confirming that option d. 25 is the correct choice.
Step-by-step explanation:
The question involves determining the length of a side of a square when the area is given as 25². We know that the area of a square (A) is calculated using the formula A = s², where 's' is the length of one side of the square. In this case, the area is 25², which means it is 25 squared, or 625 square units. To find the side length, we take the square root of the area.
√(25²) = √(625) = 25
Therefore, the length of the side of the square is 25 units, which corresponds to option d. 25. This side length is the measurement we need to describe both the perimeter and the area of the square, as well as any scale transformations it undergoes, following the rules of dimensional analysis.