Opus Palatinum de triangulis

Opus Palatinum de triangulis (The Palatine Work on Triangles) was a significant treatise on trigonometry completed by Georg Joachim Rheticus. Although published posthumously in 1596 by his student Valentin Otto, Rheticus worked on it from 1536 until his death in 1576.1

The work is notable for its extensive tables of trigonometric functions, calculated to 10 decimal places for intervals of 10 seconds of arc. Rheticus, an Austrian-born mathematician and astronomer, was also an early proponent of Nicolaus Copernicus's heliocentric theory, publishing the first account of it in 1540. Trigonometry, derived from Greek words meaning "triangle" and "to measure," historically focused on calculating missing parts of triangles and has roots in ancient civilizations like Egypt and Greece.12