
    Calculate the total distance delivery vehicles must travel to service the outermost boundary of a square-shaped delivery zone, given the length of one side of the zone in kilometers. This perimeter distance is crucial for route planning and resource allocation when servicing customers located along the zone boundaries.
    

    
def square_perimeter(a):
    """
    Calculate the total distance delivery vehicles must travel to service the outermost boundary of a square-shaped delivery zone, given the length of one side of the zone in kilometers. This perimeter distance is crucial for route planning and resource allocation when servicing customers located along the zone boundaries.
    

    """
def square_perimeter(a):
    """
    Calculate the total distance delivery vehicles must travel to service the outermost boundary of a square-shaped delivery zone, given the length of one side of the zone in kilometers. This perimeter distance is crucial for route planning and resource allocation when servicing customers located along the zone boundaries.
    

    """
    perimeter = 4 * a
    return perimeter