Plimpton 322: The Shape of Numbers - Interactive Visualization

Influential Digital

OB | c. 1800 BCE

Plimpton 322

A Catalog of Slopes

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Hover over a clay bar to analyze its geometry.

Interpretation Lens

Slope Representation

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Curator's Note

This tablet contains 15 rows of Pythagorean triples, ordered by slope from steepest (~45°) to flattest (~32°). Click any row to explore its geometry.

📜 The 2017 Discovery

"Babylonian trigonometry is exact, whereas we are accustomed to approximate trigonometry."

— Dr. Daniel Mansfield, UNSW

In 2017, mathematicians Daniel Mansfield and Norman Wildberger demonstrated that Plimpton 322 represents the world's oldest trigonometric table—predating Greek trigonometry by over 1,500 years. The Babylonians used an "exact, angle-free" approach based on ratios of sides, avoiding the approximations inherent in angle-based systems.

The tablet originally contained 38 rows; this fragment preserves 15. Using base-60 (sexagesimal) arithmetic, every ratio terminates exactly—no irrational numbers, no rounding errors.

Read the full UNSW announcement →

Deciphering Cuneiform...

Comparing Rows