Android-根据三点坐标求三角形面积

private int getArea(int x1, int y1, int x2, int y2, int x3, int y3) {
      int Area = 0;
      Area = abs((x1 * y2 + x2 * y3 + x3 * y1 - x1 * y3 - x2 * y1 - x3 * y2) / 2);
      return Area;
  }