public static double TinhDienTichDaGiac(DaGiac d)
{
double res = 0;
int j = d.Points.Count - 1;
for (int i = 0; i < d.Points.Count; i++)
{
res += d.Points[i].x * d.Points[j].y - d.Points[j].x * d.Points[i].y;
j = i;
}
return(Math.Abs(res) / 2);
}
public static double TinhChuViDaGiac(DaGiac d)
{
double res = 0;
int j = d.Points.Count - 1;
for (int i = 0; i < d.Points.Count; i++)
{
res += Coordinate.TinhKhoangCach(d.Points[i], d.Points[j]);
j = i;
}
return(res);
}
