Ib tus lej tetrahedral, lossis peb tus lej pyramidal, yog tus lej lej uas sawv cev rau lub pyramid nrog lub hauv paus peb sab thiab peb sab, hu ua tetrahedron.
Koj pom tus lej tetrahedral li cas?
Ib tus lej raug hu ua tus lej tetrahedral yog nws tuaj yeem sawv cev ua lub pyramid nrog lub hauv paus peb sab thiab peb sab , hu ua tetrahedron. Tus nth tus naj npawb tetrahedral yog cov lej ntawm thawj n daim duab peb sab. Thawj kaum tus lej tetrahedral yog: 1, 4, 10, 20, 35, 56, 84, 120, 165, 220, …
Muaj pes tsawg lub ntsej muag muaj tetrahedron?
Hauv geometry, tetrahedron (plural: tetrahedra lossis tetrahedrons), tseem hu ua daim duab peb sab, yog ib lub polyhedron tsim los ntawm plaub daim duab peb sab, rau lub npoo ncaj, thiab plaub vertex cov ces kaum. Lub tetrahedron yog qhov yooj yim tshaj plaws ntawm txhua qhov zoo tib yam convex polyhedra thiab tsuas yog ib qho uas muaj tsawg dua 5 lub ntsej muag.
Is 364 ib daim duab peb sab?
Txhua "txheej" ntawm tetrahedron yog daim duab peb sab ntawm cov dots sawv cev rau peb tus lej: yog li txhua lub tetrahedron yog cov lej ntawm peb tus lej. Tus kaum ob tetrahedral tus lej, 364, qhia peb ntau npaum li cas khoom plig peb tus neeg piav qhia tau txais tag nrho.
Pentelope nab npawb dab tsi?
Tus lej pentatope yog tus lej hauv lub xov tooj thib tsib ntawm ib kab ntawm Pascal daim duab peb sab pib nrog 5-lub sij hawm kab 1 4 6 4 1, los ntawm sab laug mus rau sab xis lossis ntawm sab xis mus rau sab laug. Thawj ob peb tus lej ntawm qhov noyam muaj xws li: 1, 5, 15, 35, 70, 126, 210, 330, 495, 715, 1001, 1365 (ib ntu A000332 hauv OEIS)
