trihedron
/traɪˈhidrən/
noun
- A solid figure with three faces, especially a triangular pyramid or a corner formed by three planes meeting at a point.
- The architect used a trihedron as the basic shape for the roof of the small pavilion.
- In geometry class, we built a trihedron out of cardboard to understand how three planes intersect.
- The crystal naturally formed a trihedron, with three smooth faces meeting at a sharp point.