nooby: how to align a mesh plane through 3 vertices

Aligning on one vertex using a constraint (copy location) and on a second vertex using another constraint (track to), i cannot use a third constraint (e.g. track to a third vertex)… But a plane does has this third degree of freedom which i cannot use here…
I also do only know the 3d-coordinates of the 3 vertices. Can i define a mesh plane by using these coordinates without calculating the plane normal by myself?
any help is appreciated!

thank you in advance!

oni

Add a plane and delete one vertex. Press the n-key to bring up the dialog (make sure global is pressed). Select each vertex and key in the coordinate in the dialog. Select the three verts and press f to make a face between them.

GreyBeard