using System; Dịch vụ cho thuê văn phòng giá rẻ tại Hà Nội[^]
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Drawing.Drawing2D;

namespace FillTriangle
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

    private void Form1\_Paint(object sender, PaintEventArgs e)
    {
        Graphics g = e.Graphics;
        
        GraphicsPath gp = new GraphicsPath(FillMode.Winding);
        
        gp.AddLine(new PointF(290, 170),new PointF(98, 128));

        gp.AddLine(new PointF(110, 170), new PointF(290, 170));

        gp.AddLine(new PointF(110, 170), new PointF(98, 128));

        g.FillPath(new SolidBrush(Color.Red), gp);
    }
}

}