Here is a good answer posted by Schnee Wittchen on another forum:-
You may use the DrawArc method of the image object. I found it a little bit tricky as it behaves different to the normal explanation, but anyway it is usable.
Syntax: img.DrawArc( x1, y1, x2, y2 ,startangle, sweepangle );
With the x1, y1, x2, y2 you define a rectangle. Within this rectangle the arc is drawn, starting at the startangle and turning clockwise by the sweepangle.