- **Lucius Annaeus Seneca the Younger **(/ˈsɛnɪkə/ SEN-ik-ə; c. 4 BC – AD 65), usually known mononymously as Seneca, was a Stoic philosopher of Ancient Rome, a statesman, dramatist, and in one work, satirist, from the post-Augustan age of Latin literature.
- Tetrahedron (Wikipedia)
In geometry, a tetrahedron (pl.: tetrahedra or tetrahedrons), also known as a triangular pyramid, is a polyhedron composed of four triangular faces, six straight edges, and four vertices. The tetrahedron is the simplest of all the ordinary convex polyhedra.