Euclid’s Elements was the book; Euclidean geometry is defined within it. https://en.wikipedia.org/wiki/Euclidean_geometry?wprov=sfti1 https://en.wikipedia.org/

Euclid’s Elements was the book; Euclidean geometry is defined within it. https://en.wikipedia.org/wiki/Euclidean_geometry?wprov=sfti1 https://en.wikipedia.org/wiki/Euclidean_geometry?wprov=sfti1