c. 1800 BCE / West Asia & North Africa
A Babylonian tablet records right-triangle numbers
Plimpton 322 preserves a sexagesimal number table revealing sophisticated relationships between the sides of right triangles.
The story
Columbia dates the tablet, associated with Larsa, to about 1820–1762 BCE. Its numbers satisfy the relation now written as a² + b² = c². Scholars disagree about its practical purpose. The table does not itself establish a surviving proof of the Pythagorean theorem or the use of modern trigonometric concepts.
Connections and context
Egyptian papyri and Chinese mathematical texts also organized procedures around problems. Similar needs could produce different numerical and teaching traditions.
Dates and precision
c. 1800 BCE Approximate year
An estimated date from the surviving evidence, not a claim about one exact year.
Representative map location
Larsa region
A representative point for the tablet's usual attribution to Larsa, not a confirmed excavation coordinate.
Representative coordinates · 31.285°, 45.854°
A marker identifies one representative place, such as a manuscript collection, laboratory or observing site. It does not mean the work happened only there, or assign a shared discovery to one country.
Bibliography
- Columbia University Libraries | Plimpton mathematical collection
- Columbia Magazine | Babylon Revisited
References are listed as plain bibliography titles. They support particular facts or context; a reference does not certify every interpretation in a story.