Ruler and compass constructions
- Wikipedia page on ruler and compass constructions in general and famously impossible constructions
- Graphical Ruler and Compass Editor Java applet allows you to place points on a canvas and then build constructions
- GCSE constructions including midpoint of a line and bisection of an angle
- Constructions for regular polygons and a table of possible constructions (heptagons are not constructable as 7 is a prime number but not a Fermat prime). This nice page includes two constructions for the 17 side regular polygon (heptakaidecagon) and one for a pentagon.
- Mathworld page on ruler and compass constructions with nice diagrams
- Crop circle patterns reduced to ruler and compass This page details a number of standard constructions and how to overlap them to make a ‘crop circle’. A lot of people think that crop circle patterns are too complex to be made overnight by Maths undergraduates with a plank, some rope, a few stout pegs, and a water bottle full of Jim Beam. Me?, I’m staying quiet….