正せい八はち面めん体たい

noun

regular octahedron

A polyhedron with eight congruent equilateral triangular faces; one of the five Platonic solids.

• 正せい八はち面めん体たいは、正せい四し面めん体たいと並ならんで基き本ほん的てきな正せい多た面めん体たいの一ひとつです。

  The regular octahedron is one of the basic regular polyhedra, along with the regular tetrahedron.