Making an ellipse follow a circular path on a canvas

I am having a problem trying to get my ellipse to follow a perfect circular path on my canvas. I had success using curves but not arcs.

<Canvas Name="WaitingCanvas"><Ellipse Name="WaitingEllipse"
                         Height="20"
                         Width="20"
                         Fill="White"><Ellipse.RenderTransform><MatrixTransform x:Name="transform" Matrix="1,0,0,1,50,100"/></Ellipse.RenderTransform><Ellipse.Triggers><EventTrigger RoutedEvent="Loaded"><BeginStoryboard><Storyboard RepeatBehavior="Forever"><MatrixAnimationUsingPath
                                        Storyboard.TargetName="transform"
                                        Storyboard.TargetProperty="Matrix"
                                        Duration="0:0:5"><MatrixAnimationUsingPath.PathGeometry><PathGeometry><PathGeometry.Figures><PathFigure StartPoint="50,100"><ArcSegment Size="50,50"
                                                                    RotationAngle="360"
                                                                    IsLargeArc="True"
                                                                    SweepDirection="Clockwise"
                                                                    Point="50,100"></ArcSegment></PathFigure></PathGeometry.Figures></PathGeometry></MatrixAnimationUsingPath.PathGeometry></MatrixAnimationUsingPath></Storyboard></BeginStoryboard></EventTrigger></Ellipse.Triggers></Ellipse></Canvas>