OK, this is an interesting one that I cannot find a good answer for.
I am trying to make a reducing pipe. It is very short. It reduces from 6" to 3" and the one side of the 3" opening is flush to the same quadrant of the 6" opening. However, when I draw a line through the quadrant points and slice a cone through the points, I end up with a very slight ellipse and I need it to be a circle with a 6" and 3" diameter.
Not entirely sure if that made sense.