tetrahedron
/ˌtɛtrəˈhiːdrən/
noun
- A solid shape with four flat triangular faces, six edges, and four vertices; a type of pyramid with a triangular base.
- The artist created a sculpture consisting of a large tetrahedron balanced on its tip.
- The molecular structure of methane forms a tetrahedron with the carbon atom at the center.
- In geometry class, we built a model of a tetrahedron out of straws and string.