using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Drawing.Drawing2D;
namespace WindowsApplication2
{
  public partial class Form10 : Form
  {
    public Form10()
    {
      InitializeComponent();
    }
    GraphicsPath get(Rectangle rect, int radius)
    {
      int diameter = 2 * radius;
      Rectangle arcrect = new Rectangle(rect.Location, new Size(diameter, diameter));
      GraphicsPath path = new GraphicsPath();
      path.AddArc(arcrect, 180, 90);
      arcrect.X=rect.Right-diameter;
      path.AddArc(arcrect, 270, 90);
      arcrect.Y = rect.Bottom - diameter;
      path.AddArc(arcrect, 0, 90);
      arcrect.X = rect.Left;
      path.AddArc(arcrect, 90, 90);
      path.CloseFigure();
      return path;
    }
    private void button1_Click(object sender, EventArgs e)
    {
      Graphics g = this.CreateGraphics();
      int width = this.ClientRectangle.Width;
      int height = this.ClientRectangle.Height;
      Rectangle rect = new Rectangle(10, 10, width - 20, height - 20);
      GraphicsPath path = get(rect, width / 10);
      g.FillPath(Brushes.Red, path);
      g.DrawPath(Pens.Yellow, path);
    }
  }
}