Scale any T-mod's edges by phi (about 1.618) to get the next larger size, or by 1/phi (about .618) to get the next smaller size. Volume changes as a third power of the scale factor, surface area as a second power.
The remainder tet is what's left when you build a T-mod recursively from phi-scaled smaller versions of itself. The T-mod is 1/120th of a rhombic triacontahedron.
Note on nomenclature: the E-mod has the same angles (shape) as the T-mod in Synergetics, but a different surface:volume ratio as it's slightly bigger. The T-mod has the same volume as the A- and B-mods in Fuller's concentric hierarchy (1/24). David does not feel bound to use this accounting system however.
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