1 finger to draw, 2 fingers to pan, zoom, and drag?

What is the syntax for drawing a path? suppose I want to draw a semicircle, the xaml is this.

<Path Stroke="Black" StrokeThickness="1"  
                                    Data="M 1,0 
                                            A 1,1 0 0 0 1,9
                                            C 1,10 1,0 1,0" Stretch="Fill" UseLayoutRounding="False" Width="26" />

What would be the c# code for this?