no historical likeness exists
c. 2000 BCEAncient Egypt
The Egyptian rope-stretchers
The 3-4-5 triangle makes a right angle, and the Egyptians used it long before anyone wrote it down.
A short story
Surveyors in ancient Egypt (four thousand years ago) used a long rope knotted at twelve equal points. Stretched taut into a triangle with sides of three, four, and five knots, the rope made a perfect right angle. They used it to lay out the corners of buildings and the boundaries of fields. They didn't know Pythagoras's name for the trick (Pythagoras himself wouldn't be born for another fifteen hundred years) but they knew the trick worked.
In their own words
Three knots, then four, then five, and the corner is true.
Paraphrased: surveying tradition described in Heron's Metrica, 1st c. CE, citing centuries-older Egyptian practice.
The lab their idea turned into
Triangle Lab
Three sides. One right angle. One famous equation.
Open Triangle Lab →