File:Overhand-folded-ribbon-pentagram.png

If a flat ribbon or strip is tightly folded into a simple overhand knot of practical knot-tying, it assumes a regular pentagonal shape.

Here a ribbon which is green on one side and blue on the other is shown folded in this way. Non-overlapped hidden edges are shown by dotted lines of the appropriate color (except that the middle of one line has been removed where it would confusingly intersect the other hidden-edge lines if shown).

If the two loose ends are joined, this becomes a trefoil knot (3_1).

Self-made image, declared to be in public domain, generated from the following PostScript source:

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