Answer:
I believe this is a Python program, not a Java one. It seems to be asking you to write a function that calculates the length of the sides of a square with a given perimeter. For example, if the perimeter is 20, the function should return the length of the side, which is 10.
Here's some Python code that should accomplish what you need:
```python
def square_perimeter(perimeter):
"""
Calculates the length of the sides of a square with a given perimeter.
"""
side_length = perimeter / 4
return side_length
Example usage:
>>> square_perimeter(20)
5
>>> square_perimeter(30)
7.5
```
Note that the function calculates the length of the sides of a square by dividing the perimeter by 4.
Hope that helps! Let me know if you have any further questions or need clarification on anything.