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Mountains and Valleys (Posted on 2006-07-19) Difficulty: 2 of 5
In origami there are two ways of folding a piece of paper. The usual way is to fold the paper upwards and if unfolded the crease is called a valley fold and from the side it looks like this: \/ If the paper is folded backward instead the crease is called a mountain fold and looks like this: /\.

If you take a strip of paper and fold it in half twice (left over right) and then unfold it without flipping you will get a figure that looks something like this from the side:


Which consists of the following sequence of folds:

/\ \/ \/

Describe the sequence of folds if the original strip of paper had been folded over 10 times and then unfolded.

No Solution Yet Submitted by Jer    
Rating: 2.5000 (2 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
re: Describe the sequence of folds (Spoiler) | Comment 4 of 9 |
(In reply to Describe the sequence of folds by brianjn)

Let us assume folds occur left to right. 
The first fold will be a valley. 
For each even number fold, for creases to the left of the initial crease, a mountain will be created on the left of each crease and a valley to the right. The mirror is true of the creases on the other side of the initial fold. A valley forms to the left and a mountain to the right.  For each odd number fold, the reverse is true.

Of the visual solution I posted earlier, my folds were right to left. Thus the the "dimples" and "pimples", beginning with the second fold, begins with the "dimple" (valley) as opposed to the  "pimple" (mountain) in Jer's example. 

Edited on July 22, 2006, 8:38 pm
  Posted by Dej Mar on 2006-07-22 20:18:59

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