Euclid's Elements has been the standard in geometry textbooks for millennia, with hundreds of editions published since the ancient Greek mathematician created it at around the year 300 BCE. One edition was particularly...

In general, a triangle is defined by its three elements. SAS, ASA, and SSS provide three well-known examples but there are many more. Bogomolny provides a table of constructions (linked to constructions) and invites...