✶ T-square
✶ T-square
Subfolder of: Aspect Patterns · Aspects
Definition: Two bodies in opposition, both square a third body (the apex or focal planet).
📐 Geometry
- a Opposition b (180°)
- a Square c and b Square c (90° each)
- c sits at the midpoint of the opposition
Arithmetic test: Apex longitude ≈ (λa + λb)/2 ± 90°; check all three orbs. Every leg must be within its own aspect orb (see the linked aspect notes).
🧭 Reading (modern Western usage)
In modern practice this configuration is read as dynamic tension discharged through the apex planet; the empty point opposite the apex (the “missing leg”) shows what balances it. Within Astrology Arith(m)etic, read each leg with the book method — body × aspect × body, coloured by sign and house — and then read the figure as a whole.
🔗 Used in
Sources
- Bil Tierney, Dynamics of Aspect Analysis (CRCS, 1983) — aspect configurations
- Robert Hand, Horoscope Symbols (Whitford, 1981) — aspects and configurations
- Claudius Ptolemy, Tetrabiblos (2nd c. CE), Book I — trans. F. E. Robbins, Loeb Classical Library 435 (1940), public-domain text at LacusCurtius: https://penelope.uchicago.edu/Thayer/E/Roman/Texts/Ptolemy/Tetrabiblos/home.html