實現效果

知識運用：

　　Graphics類的DrawPolygon (Pen pen,Point[] points)　　//繪製由一組Point結構定義的多邊形

實現程式碼：

        private void button1_Click(object sender, EventArgs e)
        {
            Graphics graphics = this.CreateGraphics();
            Pen myPen = new Pen(Color.Black,3);
            Point pt1 = new Point(80,150);
            Point pt2 = new Point(120, 20);
            Point pt3 = new Point(240, 20);
            Point pt4 = new Point(280,150);
            Point pt5 = new Point(140,240);
            Point[] myPoints = { pt1,pt2,pt3,pt4,pt5};
            graphics.DrawPolygon(myPen,myPoints);
        }