def get_start_middle_end_point(line):
    """
    Ger three point on line
    Transform it to DB.Curve

    :param line: Line
    :type line: DB.Line
    :return: Start, middle and end point of line
    :rtype: [DB.XYZ, DB.XYZ, DB.XYZ]
    """
    curve = line.GeometryCurve
    start = curve.GetEndPoint(0)
    end = curve.GetEndPoint(1)
    middle = (start + end)/2
    return start, middle, end