📅  最后修改于: 2022-03-11 14:58:58.635000             🧑  作者: Mango
(1/2)*abs( x1 * (y2 - y3) + x2 * (y3 - y1) + x3 * (y1-y2) ) , where (x1, y1) , (x2, y2) and (x3, y3) are the vertices of the triangle