Almagest and Ptolemy theorem
Almagesto: trigonometría sistemática y teorema de Ptolomeo
- Date
- c. 150 CE · confidence high
- Place
- Alexandria, Egypt
- Credited to
- Claudius Ptolemy
- People
- 👤 Claudio Ptolomeo100–170
- Field
- Knowledge & symbols
What was discovered
Table of chords calculated at half-degree intervals using Ptolemy's theorem on cyclic quadrilaterals (equivalent to the sine addition formulas) and applied to a complete geometric model of the sky.
His Geography introduced the conic projection and latitude and longitude coordinates for 8,000 places.
What it led to
- Arab and medieval astronomy
- trigonometric formulas
- Ptolemaic cartography
Built on
- Euclidean axiomatic geometryc. 300 BCE
- Hipparchus trigonometry and chord tablec. 150 BCE
- Menelaus and spherical trigonometry