Not a joinery question as such but a challenging one for experienced builders. Need help building 3 sided tapered legs on a 4 sided board.  Two sides no problem.  How to set up for third side cut?  I assume I will retain the piece removed from one side, attach to the fourth side temporarily to keep the same angle and cut.  Make sense?

Second question.  How do I cut four flutes on this tapered leg so they all taper  following the correct angle?  Obviously can cut by hand after drawing the lines but I would like to cheat and use a router.  Terry