def PolygonArea(corners):
    """
    Area of polygon given a list of vertices
    This result is due to a nifty theorem often called the Shoelace Theorem!
    """
    n = len(corners) # of corners
    area = 0.0
    for i in range(n):
        j = (i + 1) % n
        area += corners[i][0] * corners[j][1]
        area -= corners[j][0] * corners[i][1]
    area = abs(area) / 2.0
    return area