> after you finished with drawing tool then say you select the
> curve/line and show points and then how do you convert a courner point

To do this, you use Edit/Add pt, and check the "Make corner point" box, then add the new corner point nearby the point you wish to convert.

Then select the old point and delete it - you will be left with just the new corner point.

Eventually there might be some other method to convert an existing point, but for the time being just inserting a new one should get you the result that you want.

- Michael