graphics arc outer coordinates
 

Hello. Is there a way to get outer coordinates of an arch where it intersects the bounding circle/ellipsis ? In a pie chart, I want to draw labels outside of each slice. To build a slice, I use graphics.fillArc, which takes the coordinates and dimentions of the rectangle, and starting and ending angles. So I would like to get the coordinates of where the lines of that arch touch the circle, so I can determine where to put the label.

Is that possible ? If there a different way to do this ?
Thanks.