## One-Fold Origami Puzzle Raffle

This raffle is closed. Congratulations to Philip H. for being selected the lucky winner. Many thanks to all who participated!

Here’s a chance for you for some chocolate from L. A. Burdick!

Take a sheet of origami paper that is colored differently on its two sides.

If you make a valley fold along a vertical crease one-third of the way into the paper as shown above, you will end up with a model that shows exactly half of one color and half of the other color.

To locate the crease that is one-third of the way over, one can use a technique widely known to origami folders. First, one makes a crease along a diagonal. Then one pinches the halfway point along an edge. Next, make the crease that runs from the pinch over the diagonal and to a corner (as shown in the figure). This crease will intersect the diagonal at a point one-third of the way across.

## The Challenge

We ask for a single fold made over a crease that runs parallel to a diagonal that produces a model showing equal amounts of both colors. We also need a folding sequence to achieve this fold (so you don’t have to do any measuring with a ruler, for instance).

In other words, where should the diagonal fold on the left be so that the resulting model on the right shows equal parts blue and white? And, what origami folding sequence enables you to make that fold? (The figure above doesn’t show a solution.)

Send your folding sequence to us at: girlsanglepuzzler “at” gmail.com. Include your contact information in the body of the message. We will have two random drawings at midnight on September 25, 2012. One will be for student entries and the other for all entries received. So, if you are a K-12 student, you may optionally indicate this by putting “K12″ somewhere in your message. The lucky “winners” will be sent some nice chocolate from L. A. Burdick.

(We will not use your contact information for any purpose other than to deliver your prize, should you win. After the winner has been selected, all emails received will be promptly deleted. At the winner’s discretion, we will let you know who won. Anyone who makes more than one submission will be disqualified! Sorry! Also, this offer is only valid in those states in the United States where such things are legal. There is no fee to enter this puzzle contest, although donations are always welcome!)