Fold and Twist Algorithm for Some Regular n-Gons

strip length

b

n

4

5

6

7

strip

fold

twist

pentagon

steps

0

1

2

3

4

Given a strip of paper with

n

congruent parallelograms of base

b

and smaller angle

2π/n

being bisected, one can construct a regular

n

-gon using the fold and twist (FAT) algorithm.

With "pentagon" unchecked, you see just the first step of the algorithm for

n=4,5,6,7

. With "pentagon" checked, you can go through the complete algorithm for constructing a pentagon.