T-square — Astrology glossary

A T-square is a chart pattern where two planets in opposition both form square aspects to a third, creating a tense triangle with one empty leg. In a natal chart it marks an engine of drive and friction: the focal planet at the apex carries pressure from both ends of the opposition and demands constant resolution. It matters because, unlike easy patterns, the T-square pushes a person to act, often making it the most productive structure in a chart despite the strain. For example, a T-square with the apex in the tenth house can fuel relentless ambition that never feels satisfied. Astrologers watch the empty point opposite the apex, since deliberately developing that area often eases the pattern's pressure.