Some links to websites that discuss origami constructions.

• Origami Trisection of an angle How can you trisect an angle? It can be shown it's impossible to do this with ruler and compass alone, (using Galois theory) - so don't try it!!! But you may be able to find some good approximations. However, in origami, you can get accurate trisection of an acute angle.
  
  
• Tom Hull's Home Page He is an expert on the mathemctics of origami. This page has many origami related links.
  These pages are an attempt to begin collecting information on the mathematics of paper folding. Anyone who has practiced origami has probably, at one time or another, unfolded an origami model and marveled at the intricate crease pattern which forms the "blueprint" of the fold. Clearly there are some rules at play in these collection of creases. Clearly there is an origami geometry at work when paper is folded.
  Here is a review of his book Project Origami: Activities for Exploring Mathematics
  
  
• Robert J. Lang's Origami page This page contains various and sundry links to web pages that combine origami with mathematical or scientific applications.
  
  
• ORIGAMI AXIOM STEPS (TRISECTING THE ANGLE) A step-by-step account of trisecting an angle by folding paper.
  
  
• Origami and Geometric Constructions By Robert J. Lang A 50+page online book.
  
  
• Origami as a Field of Mathematics A collection of links from Math on the Street
  
  
• Wolfram origami site
  
  
• Unfolding Mathematics with Unit Origami