public partial class Form1 : Form{ public Form1() { InitializeComponent(); } private void Form1_Load(object sender, EventArgs e) { Form f = new Form(); f.Height = 350; f.Width= 350; //Creating circle path System.Drawing.Drawing2D.GraphicsPath path = new System.Drawing.Drawing2D.GraphicsPath(); path.AddEllipse(0, 0, 300, 300); //Creating the region from the circle path f.Region = new Region(path); f.Show(); }}