Final answer:
To determine the side length of a square with a perimeter of 36, divide the perimeter by 4, which yields a side length of 9. Therefore, the correct answer is d. 9.
Step-by-step explanation:
To find the length of one side of a square when given the perimeter, we need to understand that the perimeter of a square is equal to the sum of all its sides. Since a square has four equal sides, we can write the equation for the perimeter P of a square as P = 4a, where a is the length of one side.
In this case, the perimeter is given as 36. Therefore, we can set up the equation: 36 = 4a. To find the length of one side, we divide both sides of the equation by 4, resulting in a = 9. So, the length of one side of the square is 9 units.
The correct answer is d. 9.