Creating a Plane from Draw Curve shapes?

 From:  Bob (PHOTON713)
Is it possible to create a shape using Draw Curve tools that results in a plane that can be
extruded? Or, must I always start with a Solid Tools plane and draw on the needed shape and
remove the excess and extrude? While testing the ability to fillet or chamfer the diagonal edge
of a triangle I assumed that connecting 3 lines in the shape of a triangle would result in a plane?