如何由任意四個座標判斷其圖形,長度,及面積 / C++ / 程式設計俱樂部
2004/4/13 下午 11:22:44 如果已知四個點的順序.. PS.已排序..順時針或是逆時針均可 可以下程式計算面積 (LINE 1 = x1,y1 to x2,y2) (LINE 2 = x2,y2 to x3,y3) (LINE 3 = x3,y3 to x4,y4) (LINE 4 = x4,y4 to x1,y1) area1 = (y1+y2)*(x1-x2)/2.0; area2 = (y2+y3)*(x2-x3)/2 ......