Mathematician:Theaetetus of Athens

Mathematician
Greek mathematician whose principal contribution was the material on irrational lengths, included in Book $\text X$ of.

Also proved that there are precisely five regular convex polyhedra.

All we know about him was what (who rated him highly) wrote about him.

Nationality
Greek

History

 * Born: about 417 BCE in Athens, Greece
 * Died: about 369 BCE in Athens, Greece

Theorems and Definitions

 * Five Platonic Solids
 * Much if not all of the content of Book $\text X$ of