The perimeter of a square can be calculated using the formula P = 4s, where s is the length of one side of the square.
In this case, one side is given as 3x + 2. To find the perimeter, we substitute this expression into the formula:
P = 4(3x + 2)
Now, we can distribute the 4:
P = 4 * 3x + 4 * 2 = 12x + 8
Therefore, the expression that represents the perimeter of the square is 12x + 8.