Almost right from the start I noticed that the geometry of many formations was based on the same pattern. The diagram on the right shows this basic pattern. It is very simple to construct and you most likely have made this pattern already many times.
Click on the diagram to find out how it can be constructed.

The 1995 formation at Winterbourne Bassett was one of the very first formations I tried to reconstruct. This formation has fascinated me right from the moment I visited it back in 1995. Perhaps the fascination has something to do with my mathematical background. For me the formation has a strong link with the famous theorem a2+b2=c2 of Pythagoras, the Greece mathematician who lived around 450 BC.

The formation at Winterbourne Bassett in 1997, also known as the 'Harlequin', was a real eye-opener for me. It was during the reconstruction of this formation that I noticed for the first time how different elements within a crop circle were all related to each other. How it is logical that you will find diatonic ratios in crop circles. Read also Size, Placing and Ratios within the section Crop Circle Geometry!

When Michael Glickman saw the formation at Little Bury Green in 1996, he made the remark: "Ah, three bananas in a basket". This was reason enough for me to look if this formation was indeed just 'three bananas in a basket'. Part of it looks perhaps just like bananas, but the formation in totally is geometrically spoken a real beauty. 
Click on the image and judge for your self.

A formation of such beauty in oilseed rape screams for a closer inspection. And that is what I did. I took a closer look and again I found that the formation could easily be reconstructed and that the basic pattern formed the basis for this formation as well. If you look at the reconstruction you will notice that it resembles the reconstruction of the formation at Little Bury Green.

Barbury Castle 1992. The so-called 'Mother of all pictograms'. Of course this pictogram could not fail in the row of formations I have analised. Notice how this formation doesn't look 100% perfect. One of the sides of the triangle is crooked and the spiral looks turned in a strange way. But as with the Liddington Castle formation, these irregularities again could very well be reconstructed. Beside of that this formation had one very special construction point. 
Read also Construction Points in the section Crop Circle Geometry.

It is especially the ring round the formation that makes this crop circle so interesting. While reconstructing this formation, I noticed that it needed six construction points that were lying away from the main pattern. It turned out that these six points were located exactly where the ring was. An intriguing combination of size, placing and construction points
Read also Construction Points in the section Crop Circle Geometry.

Interlocking spirals! That was the general opinion when this beautiful formation appeared in 1999 at the foot of Hackpen Hill. And indeed, I thought the same. The question was: 'Which kind of spirals are we looking at?' So I investigated the formation and found to my own amazement that the formation was not based on spirals at all! It turned out to be a clever interaction of semi circles. A real beauty that will be remembered for years.

This very interesting crop circle appeared in 1999 just below Barbury Castle. Interesting to look at from the outside, but foremost very interesting if you look inside. The internal geometry of this formation shows how the different elements of the formation are not random. The size, shape and place of the crescents could only be the way they were! It is a showcase example of what I already earlier noticed at the Winterbourne Bassett formation of 1996. 
Read also Size, Placing and Ratios in the section Crop Circle Geometry.

Pentagrams and pentagons intrigue many people. They think the shape of the pentagram has a special quality, whatever that is. Pentagonal geometry did also appear in crop circles. First at the outside. 
Read Pentagonal Geometry in the section Crop Circle Geometry for more information. In later years crop circles appeared that were fully based on five fold geometry. Here I show how to construct five-fold geometry.

The Bishops Cannings formation of 1997 is a classic example of a formation that is based on five-fold geometry. This cannot be overlooked, no matter how hard you try. And although the formation is pretty straightforward it also contains some beautiful geometrical elements. Take a look and try to find them for yourself.

One of the most famous crop circles ever appeared near Avebury in 1994. Of course the combination of a monumental crop circle beside a monument like Avebury contributed to its fame, but the formation on itself was already stunning enough to be in the top ranks. I couldn't resist studying its internal geometry and stumbled on something really special. It turned out that the formation is not solely based on ten-fold geometry but is also interlocked with the three-fold geometry of 'the basic pattern'.

Using sticks of equal length it is possible to make a perfect heptagram, but using ruler and compasses it is impossible! There is no known method. Though there are several methods that come close. Here I show a method that is relatively simple and near perfect. If you use the method the traditional way, that is with a compasses on paper, you won't even notice that it is not 100% perfect.

It does not often happen that a crop circle based on seven-fold geometry appears. In 1998 it did at Tawsmead Copse. And it was a special one. It was beautiful and it was based on seven-fold geometry. But I found something that made it real special. In the Crop Circle Geometry section under Construction Lines you can read what this 'something' was. Here you can find all the construction steps needed and form your own opinion on this 'something'.

Although crop circles based on seven-fold geometry don't appear often, in 1998 there was more then one. The first one appeared in the Eastfield near Alton Barnes. It had an intriguing shape and an even more intriguing internal geometry. The seven-fold formation at Tawsmead Copse appeared a month after the Eastfield formation, but the geometry of the Eastfield looked like an extension of the Tawsmead Copse geometry. It looked like the appearance should have been the other way round.

It is impossible to construct 100% precise nine-fold geometry using a ruler and compasses, though there are different methods that come close. The method shown here is perhaps the most simple, is almost 100% accurate and has oddly enough a six pointed star as starting point!