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This content is taken from the Davidson Institute of Science Education at the Weizmann Institute of Science's online course, Flexagons and the Math Behind Twisted Paper. Join the course to learn more.
2.1

# Introduction

This week we’re going to take a look at advanced flexagons and we’ll start with two important flexagons, the straight-strip, cyclic, hexa-hexa-flexagon (6-6-flexagon), and the straight-strip, cyclic, tetra-octa-flexagon (4-8-flexagon).

Notice that I have to use a lot of words to describe what we’re going to make, and I’m still not sure that you have a clear picture of what we are making! In any case, first, we’re going to take a straight strip of 38 equilateral triangles, 19 on each side, coloured with 6 different colours and fold it into a hexagon to form a hexa-hexa-flexagon with 6 faces, one for each colour. You have already seen the Tuckerman diagram for this flexagon in the quiz! We’ll explore the flexagon and look at some of its interesting properties.

Our second flexagon will also be made from a straight strip. This time, the strip has 34 isosceles right-triangles, 17 on each side, that are coloured using 4 different colours. This strip can be folded into a four-faced square flexagon with 8 triangles on each face. Let’s get going then!

# Discussion

Any questions? Feel free to ask and don’t be shy :-)