circular airspace

Hi, All
How to create a circular airspace? GoogleEath only draws straight lines AFAIK.
Better yet, how to create a circular airspace (CTR) that is partially overlaped by another circular airspace (TMA)?
Regards
BitBrusher
How to create a circular airspace? GoogleEath only draws straight lines AFAIK.
Better yet, how to create a circular airspace (CTR) that is partially overlaped by another circular airspace (TMA)?
Regards
BitBrusher