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Which Euclidean postulate allows a line segment to be extended indefinitely?
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Euclid
Euclid, coloured woodcut, 1584. His Elements, a treatise on geometry and mathematics, is one of the most influential books ever written.
The Euclidean postulate that allows a straight line segment to be extended indefinitely is the second postulate.1
In the foundational work of Euclid, these five axioms serve as the basis for all logical deductions in Euclidean geometry. While the second postulate addresses the extension of lines, the fifth, known as the parallel postulate, is particularly famous for its role in the development of non-Euclidean geometries.1