Regular solids
Volume XIII of Elements deals with the construction of the five regular Platonic solids (pyramid, cube, octahedron, dodecahedron, icosahedron) inside a given sphere.
It doesnt have a specific title. But i feel that it covers the pythagorean proofs of Theaetetus :)
The thirteenth book of "Euclid's Elements" is called regular solids. In this final book, Euclid names and describes the properties of the five regular solids and ends it by proving no other regular solids exist.
Platonic solids
It was called The Elements the 13 volume
Euclid's Elements is a set of thirteen mini-books and sometimes found as one whole book. The thirteenth book it titled Regular Solids.
Element's Volume XIII, along with Volumes XI and XII, examines three-dimensional figures. Volume XIII includes the construction of pyramids, cubes, octahedrons, dodecahedrons, and icosahedrons (the five regular Platonic solids) in a sphere.
Euclid wrote the famous book called Elements
There are 13 books in Euclid's Elements. The title of Book XIII is " Regular solids."
Elements
compositions
Elements