Three rods, ceiling mounted. This page has a great overview of formal vs. casual and ideas for types of drapery. This is an example of ripplefold.
Anothony Bay Pole Door curtain, One bend, Graphite
Pivoine & Sage ~ Hare/Rabbit curtains.
Cornice melds with Ceiling Crown Molding idea - will hide traverse rod with sheers nicely!
Bay window curtain poles - The Bradley Collection
Cream walls and curtains, neutral colour scheme, curtains for bay window
Curtain Poles and Tracks, Curtain Rods from Spring Crest Curtains and Blinds Gold Coast
Blog - Apex, Angles & Pleats Curtain Poles-Tracks-Rails-Bay Window Poles-Silent Gliss-Autoglide-Swish
Chesneys in a modern setting
Bay window: embroidered linen curtains (Nina Campbell Syvana Arboretum) with triple pinch pleats , lined and interlined on fabric covered lath