It's called a "ternary diagram". Useful when you have three quantities that must add up to a fixed value, but can be applied to other situations as well.
Bob at PC
________________________________________
From: phys-l-bounces@carnot.physics.buffalo.edu [phys-l-bounces@carnot.physics.buffalo.edu] On Behalf Of ludwik kowalski [kowalskil@mail.montclair.edu]
Sent: Tuesday, January 04, 2011 2:10 PM
To: Forum for Physics Educators
Subject: [Phys-l] Another t trivial question
Suppose I create a 2D coordinates system that has three axes, at 60
degrees with respect to each other. It has three triants (what is a
better name three regions in such space?). Suppose I use this system
to describe rooms. Suppose the axes are labeled (a) for absolute
pressure, (b) for absolute temperature, and (c) for floor area. Is
there anything heretical in doing this?