"ib daim duab uas khi los ntawm yim lub dav hlau ntsej muag, " 1560s, los ntawm Greek oktahedron, neuter ntawm oktahedros "yim-sided," los ntawm okta- "yim" (saib octa -) + hedra "lub rooj; lub ntsej muag ntawm cov khoom geometrical, "los ntawm PIE hauv paussed- (1) "to zaum." Related: Octahedral.
Vim li cas thiaj hu ua octahedron?
Lo lus octahedron yog muab los ntawm Greek lo lus 'Oktaedron' uas txhais tau tias 8 ntsib. Ib qho octahedron yog polyhedron nrog 8 lub ntsej muag, 12 npoo, thiab 6 ntsug thiab ntawm txhua qhov vertex 4 npoo sib ntsib.
lo lus octahedron txhais li cas?
: a khoom khi los ntawm yim lub dav hlau ntsej muag.
Vim li cas octagonal pyramid hu ua octahedron?
Hauv geometry, ib qho octahedron (plural: octahedra, octahedrons) yog polyhedron nrog yim lub ntsej muag, kaum ob ntug, thiab rau vertices. Lo lus feem ntau yog siv los xa mus rau qhov tsis tu ncua octahedron, Platonic cov khoom tsim los ntawm yim daim duab peb sab sib npaug, plaub qhov sib ntsib ntawm txhua qhov vertex.
Lwm lub npe ntawm octahedron yog dab tsi?
Nyob rau hauv nplooj ntawv no koj tuaj yeem nrhiav tau 8 lub ntsiab lus, cov lus qhia, cov lus qhia, thiab cov lus hais txog octahedron, xws li: equilateral, icosahedron, dodecahedron, tetrahedra, octahedra, stellate, polyhedron thiab equilateral-daim duab peb sab.
