https://doi.org/10.1351/goldbook.15365
Triangular plot (usually an equilateral or right-angled triangle) whose vertices represent the pure components of a ternary system at constant temperature and pressure. Any point within the triangle represents the composition in terms of the two independent mole (or mass) fractions. Lines parallel to the sides of the triangle represent constant proportions of the respective components (isopleths).
Notes:
- In an isobaric diagram, an axis perpendicular to the plane of the triangle may be added to represent temperature.
- In addition, any triangle of any shape, including any triangle within the main triangle, can be used to obtain the composition of the system represented by a point within the triangle in terms of the compositions represented by its vertices.