import math


def GetAngle(left, right, support):
    """
    Return angle of the three points.
    Args:
        left: Left point
        right: Right point
        support: Supported point

    Returns:
        Angle
    """
    kk = 1 if (left[1] > right[1]) else -1

    x1 = left[0] - support[0]
    y1 = left[1] - support[1]

    x2 = right[0] - left[0]
    y2 = right[1] - left[1]

    cos = (x1 * x2 + y1 * y2) / math.sqrt(x1 * x1 + y1 * y1) / math.sqrt(x2 * x2 + y2 * y2)
    return kk * (180.0 - math.acos(cos) * 57.3)