Arbortext IsoDraw > User's Reference > Palette Window Toolbox > Elements > Ellipse > Converting the Element
  
Converting the Element
To convert ellipses to Bézier paths, choose Element > Convert > into Bézier parts. If you have deleted individual segments of the ellipse, the ellipse may be converted into several Bézier paths.
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A Bézier path cannot be converted back into an ellipse afterwards.