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# The Pentagram The Pentagram (or Pentangle) is a 5-pointed star. You may think it has something to do with witchcraft, but in fact it is more famous as a magical symbol and is also a holy symbol in many religions. In fact, this simple figure is quite amazing.
 Inside a Pentagram is a Pentagon  You can make a pentagram by first drawing a pentagon, then extending the edges. Or by drawing lines from corner to corner inside a pentagon.

## Ratios But the pentagram has a special number hidden inside called the Golden Ratio, which equals approximately 1.618 a/b = 1.618... b/c = 1.618... c/d = 1.618... When I drew this, I measured the 4 lengths and I got a=216, b=133, c=82, d=51. So let's check to see what the ratios are: 216/133 = 1.624... 133/82 = 1.622... 82/51 = 1.608... If I had drawn and measured more accurately, I would have been even closer! Why not have a go yourself: Draw a regular pentagram Measure the lengths Calculate the ratios

## Irregular Pentagram

So far we have only been looking at the regular pentagram (all sides and angles equal), but there are also irregular pentagrams. 