noun
- plural of octahedron; three-dimensional geometric shapes with eight triangular faces
Usage: geometry; mathematics
Examples
- The crystal formed perfect octahedra when it cooled slowly.
- Students learned to calculate the volume of octahedra in geometry class.
- The mineral specimens displayed beautiful octahedra shapes.
- Regular octahedra have eight equilateral triangular faces.
- The teacher used models of octahedra to explain three-dimensional geometry.
- Diamond crystals often naturally form as octahedra.