Srichakra

Srichakra is also known as Sriyantra. In Tripuratapini Upanishad of Atharvana Veda, there is a detailed description of the construction of Srichakra, its merits and its spiritual power. The diagram consists of nine interwoven isosceles triangles. Four pointing upwards representing Sakti, the primodial female essence of dynamic energy, and five point downwards, representing Siva, the primordial male essence of static wisdom. The triangles are arranged in such a way that they produce 43 subsidiary triangles.

The mathematical interest in the Srichakra or Sriyantra lies in the construction of the central nine triangles, which is a more difficult problem than might first appear. A line here may have three, four, five or six intersections with other lines. The problem is to construct a sriyantra in which all the intersections are correct and the vertices of the largest triangles fall on the circumference of the enclosing circle. Kulaichev, the Russian mathematician, goes into the "higher" mathematics implicit in constructing different types of Srichakras.

There is however, a curious fact about all the correctly constructed Sriyantras, whether enclosed in circles, or in squares. In all such cases the base angle of the largest triangle is about 51 1/2 degrees. The monument that comes to mind when this angle is mentioned is the Great Pyramid at Gizeh in Egypt, built around 2600 B.C.

Source : The Origin and History of Mathematics, V.Lakshmikantham, S.Leela and J.Vasundhara Devi, Florida Institute of Technology, USA, Cambridge Scientific Publishers.