> it's not planed to have "circurlar lines helpers" ?

I don't have any plan for this right now... It's a bit more difficult to think of a way to do this easily since a circle is a planar shape, it isn't automatically fully defined by only 2 points unless you fix it to a particular plane.

The nice thing about construction lines are that they are fully defined by the 2 points that you use to create them (point you start dragging on, and point you release on).

I'm not sure that "construction circles" are needed in enough situations to be useful enough to have a special mechanism for them instead of just drawing a circle and erasing it later...

Also a construction line is different from a regular line because it has infinite extension... But I'm not sure what a "construction circle" would give different from just drawing a regular circle as a helper.

- Michael