A solid figure with ten plane faces.
- ‘The two models in the top row are compounds of two decahedra each. The model in the bottom row left and right is a nonconvex octahedron, consisting of 4 squares and 4 triangles.’
- ‘Like the elongated shapes, the pentagons and hexagons are also characterized by a fivefold symmetry; we thus observe regular decahedrons and icosahedrons.’
- ‘The cleaning layer has fully reticulated pores in a uniform network of substantially equilateral cells 34, such as tetrahedrons, truncated octahedrons and decahedrons.’
- ‘Now fold, crease, decorate, and glue your decahedron, following the same hints given on the tetrahedron page.’
- ‘On this picture you will see two types of crystals: bigger ones - decahedrons - this is sugar and round ones - this is salt.’
Early 19th century: from deca- ‘ten’+ -hedron, on the pattern of words such as polyhedron.
We take a look at several popular, though confusing, punctuation marks.