Three component phase diagram

In a three component phase diagram, the proportions of the three variables A, B, and C must (normally) sum to 100% or 1.0. If we know A and B we can calculate C : 100%-A-B=C (or 1-A-B=C). Because the three proportions cannot vary independently - it is possible to graph the intersection of all three variables in a two dimensional manner (two degrees of freedom).**Three component phase diagram**

Three component phase diagram (above):

Blue area (center): A =
20% , B = 10% and C = 70%
--> A + B + C = 100%