# Definition:Regular Tetrahedron/Historical Note

Jump to navigation
Jump to search

## Historical Note on the Regular Tetrahedron

The concept of a **regular tetrahedron** is not mentioned explicitly by Euclid in *The Elements*.

The first reference to it is in Proposition $13$ of Book $\text{XIII} $: Construction of Regular Tetrahedron within Given Sphere:

In the words of Euclid:

*To construct a pyramid, to comprehend it in a given sphere, and to prove that the square on the diameter of the sphere is one and a half times the square on the side of the pyramid.*

(*The Elements*: Book $\text{XIII}$: Proposition $13$)

According to the Pythagorean tradition, the **regular tetrahedron** was the symbol for the element fire.

## Sources

- 1986: David Wells:
*Curious and Interesting Numbers*... (previous) ... (next): $4$ - 1997: David Wells:
*Curious and Interesting Numbers*(2nd ed.) ... (previous) ... (next): $4$