You can find this year’s Pythagorean dates – dates that fit into the Pythagorean theorem – with a simple spreadsheet that finds right angle days.

## A Brief Guide to the Euclidean Postulates Found in Euclid’s Elements

## Elements of Geometry: A Brief Guide to the Euclidean Axioms

Euclidean geometry is based on Euclid’s axioms and postulates. What do the Euclidean axioms say, and why are they so important in math?