tetrahedrons
Triangular-based pyramids collectively
Tetrahedrons are three-dimensional shapes with four triangular faces—the simplest possible polyhedron.
Each face meets three others at four vertices.
The regular tetrahedron, with all faces equilateral triangles, appears in chemistry as the shape of certain molecular structures: A methane molecule arranges its hydrogen atoms at the corners of a tetrahedron.
Also pluralized as tetrahedra.
Corner points of shapes
- edgesOuter limits or boundaries
- facesFront of heads
- triangularThree-cornered in form
- simplexUndivided, one-direction transmission
three-dimensional · convex · solid · pyramid · vertex · face · edge · volume
Load-bearing beam arrangement
- geodesicShortest curved-surface path
- tensegrityStructure balanced by pull
- latticeOpenwork of crossed strips
- frameworkUnderlying support system
spaceframe · molecular structure · methane · silica · carbon · scaffolding · rigid · modular
Twenty-faced regular solid
- octahedronEight-faced geometric solid
- dodecahedronTwelve-faced regular polyhedron
- cubeSix-squared-faced solid
- EuclideanFlat-space geometry type
Invariance under angular displacement
- reflectionReturned light or thought
- axisRotation reference line
- invariantRemaining always constant
- congruenceState of agreement
isometry · transformation · chiral · achiral
Having four straight boundaries
- tabletopHorizontal furniture surface
- roleplayingAssuming fictional identities
- Dungeons and DragonsFantasy roleplaying game system
- randomOccurring without pattern
probability · RPG · gaming · pip · roll · percentile
vertices
Corner points of shapes
- edgesOuter limits or boundaries
- facesFront of heads
- triangularThree-cornered in form
simplex · three-dimensional · convex · solid · pyramid · vertex · face · edge · volume · surface area
truss
Load-bearing beam arrangement
- geodesicShortest curved-surface path
- tensegrityStructure balanced by pull
- latticeOpenwork of crossed strips
framework · spaceframe · molecular structure · methane · silica · carbon · scaffolding · rigid · modular · interlocking
icosahedron
Twenty-faced regular solid
- octahedronEight-faced geometric solid
- dodecahedronTwelve-faced regular polyhedron
- cubeSix-squared-faced solid
rotational symmetry
Invariance under angular displacement
- reflectionReturned light or thought
- axisRotation reference line
- invariantRemaining always constant
congruence · isometry · transformation · chiral · achiral
four-sided
Having four straight boundaries
- tabletopHorizontal furniture surface
- roleplayingAssuming fictional identities
- Dungeons and DragonsFantasy roleplaying game system
random · probability · RPG · gaming · pip · roll · percentile
- tank obstaclestank trap, anti-tank mines, dragon's teeth, concrete blocks, steel beams
tetrahedronsicosahedrons
Twenty-faced geometric solids
icosahedra · dodecahedrons · cubes · hexahedrons · octahedrons