Olympic triangle be perfectly sharp, either, since it is a course. Traditionally the configuration of the triangle is an equilateral triangle (3 equal sides and 3 equal angles of 60 degrees) with a ratio of the windward leg to a reaching leg being 1:1. In that case the course length for the 9 legs described above is 9 times the length of the windward leg. The angle at each point of the triangle is 60 degrees. The windward leg is generally aligned with the average wind direction. Another configuration is a triangle with a right angle at the wing mark and 45
Sierpinski triangle the Sierpinski triangle. The Sierpinski triangle may be constructed from an equilateral triangle by repeated removal of triangular subsets: Each removed triangle (a "trema") is topologically an open set. This process of recursively removing triangles is an example of a finite subdivision rule. The same sequence of shapes, converging to the Sierpinski triangle, can alternatively be generated by the following steps: Note that this infinite process is not dependent upon the starting shape being a triangle—it is just clearer that way. The first few steps starting, for example, from a square also tend towards a Sierpinski triangle. Michael Barnsley used