how to draw ellipse resizable in .net winforms

private void panel1_MouseMove(object sender, MouseEventArgs e)
{
Cursor.Current = Cursors.Cross;
Graphics g = panel1.CreateGraphics();
Pen p = new Pen(Color.Red);
Rectangle rect = new Rectangle(0, 0, 200, 100);
g.DrawEllipse(p, 50, 50, x, x);
}

private void panel1_MouseDown(object sender, MouseEventArgs e)
{
Point p1 = new Point(e.X, e.Y);
x = p1.X;
y = p1.Y;
panel1.Invalidate();


}
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how to this i have done this but by dong this the ellipse is not resizabel
i need resiazble ellipse.