Can I make The Shape of Form linear on C#?

Question

is there a way to make form shape linear i I could make it as circle i used a GraphicsPath

       GraphicsPath path = new GraphicsPath();
        RectangleF rec = new RectangleF(0, 0, 100, 150);
        path.AddEllipse(rec);
        this.Region = new Region(path);

but when i try to make it as line i try this code

         GraphicsPath path = new GraphicsPath();
        path.AddLine(0,0,200,200);
        Cursor.Position = new Point(200, 200);
        this.Region = new Region(path);

but Nothing happened the form looks like disappear So Can Someone help me please