Introduction
Flexagons are flat models, usually constructed by folding strips of paper, that can be flexed or folded in certain ways to reveal faces besides the two that were originally on the back and front.
Tools
Parts
Video Overview


Take an A4 size paper

Fold the paper into half

Then fold one of the corners to the edge of the opposite side of the paper to create a rightangled triangle plus a rectangular strip below



Cut off this extra rectangular strip

Unfold the rightangled triangle and notice a rectangle made up of 2 squares; i.e. length:breadth is 2:1

Again fold both the edges along the mid line to get a long doubled up rectangular strip.



Fold the strip in half to get the halfway line

Fold the edges to the halfway line to get the quarter lines

Fold the edges to the quarter line to get the 1/8th lines on both the sides

Take one edge and crease it to one fold to get 1/8th on the other side of the half. Repeat with the other edge.

Strip will be divided into 8 equal parts



Fold the paper in the middle leaving the open line outside

Draw a rhombus at the centre and 2 diagonals joining 4 corners

Repeat the same on the other side of the fold.



Tear one eighth of the strip off

Now sharply crease all the 10 slant lines with the help of a ruler

Tuck one section of one end into the other end to make a prism



Your prism is ready

Fold half diamonds on all sides to the inside

Fold 3 diamondshaped petals to the inside on the top and bottom



How many triangles are visible and what type of triangles are they?

Can you make a bigger model?

Observe if the direction of pictures are appearing in the same direction while continuously flexing for a long time

Can you make a flexagon with 3:1 or 4:1 ratio of sides?
