Triangular Plot

Triangular Plot- a two-dimensional map in which three variables are mapped. The ratios of the three variables are plotted as positions within an equilateral triangle. 

http://www.fas.org/irp/imint/docs/rst/Sect16/Sect16_3.html

A triangular plot can depict interactions with variables in different positions or how the different variables relate to each other. In the above diagram, the variables are the fields listed along the outside of the triangle and the data points are the specific sciences listed within the triangle. Chemistry is very much a disciplinary science and an earth system science, but not at all a decision making field. Politics is very much a decision making field, but not at all a disciplinary science or an earth system science. Engineering is squarely in the middle of the disciplinary sciences, earth system sciences, intergration, interpretation, and decision making.