
    Design a function that calculates the total length of smart parking sensors needed to fully equip the perimeter of a circular parking zone, where the sensors must be installed continuously along the boundary to monitor vehicle entry and exit points effectively. The input will be the radius of the circular parking zone measured in meters from its center point to the edge.
    

    
def circle_circumference(r):
    """
    Design a function that calculates the total length of smart parking sensors needed to fully equip the perimeter of a circular parking zone, where the sensors must be installed continuously along the boundary to monitor vehicle entry and exit points effectively. The input will be the radius of the circular parking zone measured in meters from its center point to the edge.
    

    """
def circle_circumference(r):
    """
    Design a function that calculates the total length of smart parking sensors needed to fully equip the perimeter of a circular parking zone, where the sensors must be installed continuously along the boundary to monitor vehicle entry and exit points effectively. The input will be the radius of the circular parking zone measured in meters from its center point to the edge.
    

    """
    perimeter = 2 * 3.1415 * r
    return perimeter