Euclid's Elements

This article explores how Euclid's ancient geometry interacts with all aspects of human thought and life.

Euclid's fourth axiom says that all right angles are equal. But isn't that obvious?

Five basic facts from the father of geometry.

The Plus anniversary year — A word from the editors

The famous mathematician Euclid is credited with being the first person to axiomatise the geometry of the world we live in - that is, to describe the geometric rules which govern it. Based on these axioms, he proved theorems - some of the earliest uses of proof in the history of mathematics.

Starting in this issue, PASS Maths is pleased to present a series of articles about proof and logical reasoning. In this article we give a brief introduction to deductive reasoning and take a look at one of the earliest known examples of mathematical proof.