How to change the stroke style ?

Ellipse myCircle = new Ellipse();
myCircle.Width = 400;
myCircle.Height = 400;
myCircle.Stroke = Brushes.PeachPuff;
myCircle.StrokeThickness = 25;
myCircle.ToolTip = "Bold Circle";
Canvas.SetTop(myCircle, 0);
Canvas.SetLeft(myCircle, 0);
canvas.Children.Add(myCircle);

Ellipse myCircle2 = new Ellipse();
myCircle2.Width = 400;
myCircle2.Height = 400;
myCircle2.Stroke = Brushes.Black;
myCircle2.StrokeThickness = 1;
Canvas.SetTop(myCircle2, 0);
Canvas.SetLeft(myCircle2, 0);
canvas.Children.Add(myCircle2);