def get_point(msg):
    """(str) -> tuple
    prints a message specified by <msg> and allows the user to enter the
    (x, y, z) coordinates of a point. 
    Returns the point as a tuple
    """
    print(msg)
    x = float(input('Enter x coordinate: '))
    y = float(input('Enter y coordinate: '))
    z = float(input('Enter z coordinate: '))

    return x, y, z