noun
- a solid figure with four triangular faces
Usage: geometry
Examples
- The tetrahedron is one of the five Platonic solids.
- Each face of a tetrahedron is an equilateral triangle.
- The students built a tetrahedron using straws and clay.
- A tetrahedron has four vertices and six edges.
- The pyramid-shaped dice is actually a tetrahedron.
- In chemistry class, we learned that methane has a tetrahedral structure.