def area_polygon(points):
    """ Given an ANGLE ORDERED array points of [[x], [y]], find the total area by summing each successsive
    triangle with the centre """
    import numpy as N
    x, y = points
    n_tri = len(x) - 1
    cenx, ceny = N.mean(x), N.mean(y)
    area = 0.0
    for i in range(n_tri):
        p1, p2, p3 = N.array([cenx, ceny]), N.array([x[i], y[i]]), N.array([
            x[i + 1], y[i + 1]])
        t_area = N.linalg.norm(N.cross(p2 - p1, p3 - p1)) / 2.0
        area += t_area
    return area
