Dab tsi yog lub pyramid tsis tu ncua: txhais, hom, khoom

Hauv kev tshaj tawm no, peb yuav xav txog cov ntsiab lus, hom (daim duab peb sab, quadrangular, hexagonal) thiab cov khoom tseem ceeb ntawm lub pyramid tsis tu ncua. Cov ntaub ntawv nthuav tawm yog nrog rau cov duab kos duab kom pom kev zoo dua.

Lub ntsiab lus ntawm lub pyramid tsis tu ncua

Tsis tu ncua pyramid - qhov no, lub hauv paus ntawm uas yog ib txwm polygon, thiab sab saum toj ntawm daim duab yog npaj rau hauv nruab nrab ntawm nws lub hauv paus.

Feem ntau hom pyramids tsis tu ncua yog daim duab peb sab, quadrangular thiab hexagonal. Cia peb xav txog lawv hauv kev nthuav dav ntxiv.

Hom pyramid li niaj zaus

Tsis tu ncua daim duab peb sab pyramid

• Base - txoj cai / equilateral daim duab peb sab ABC.
• Lub ntsej muag sab yog zoo tib yam isosceles daim duab peb sab: ADC, BDC и ADB.
• Projection vertices D ntawm lub hauv paus - point O, uas yog qhov chaw sib tshuam ntawm qhov chaw siab / nruab nrab / bisectors ntawm daim duab peb sab ABC.
• DO yog qhov siab ntawm lub pyramid.
• DL и DM - apothemes, piv txwv li qhov siab ntawm sab ntsej muag (isosceles daim duab peb sab). Muaj peb nyob rau hauv tag nrho (ib qho rau txhua lub ntsej muag), tab sis daim duab saum toj no qhia ob thiaj li tsis txhob overload nws.
• ⦟DAM = ⦟ DBL = a (lub kaum sab xis ntawm sab tav thiab puag).
• ⦟DLB = ⦟DMA = b (lub kaum sab xis ntawm sab ntsej muag thiab lub hauv paus dav hlau).
• Rau xws li lub pyramid, cov kev sib raug zoo hauv qab no yog qhov tseeb:

  AO: OM = 2:1 or OB:OL = 2:1.

Nco ntsoov: yog hais tias ib tug li niaj zaus daim duab peb sab pyramid muaj tag nrho cov npoo sib npaug, nws kuj hu ua muaj tseeb .

Tsis tu ncua quadrangular pyramid

• Lub hauv paus yog ib txwm quadrilateral ABCD, nyob rau hauv lwm yam lus, ib square.
• Lub ntsej muag sab yog sib npaug isosceles daim duab peb sab: Cov xwm txheej dav dav ntawm kev yuav khoom, BEC, CED и AED.
• Projection vertices E ntawm lub hauv paus - point O, yog qhov kev sib tshuam ntawm cov kab pheeb ces kaum ntawm lub square ABCD.
• EO - qhov siab ntawm daim duab.
• EN и EM - apothemes (muaj 4 nyob rau hauv tag nrho, tsuas yog ob leeg tau qhia hauv daim duab ua piv txwv).
• Cov kaum sib npaug ntawm sab ntug / ntsej muag thiab lub hauv paus yog qhia los ntawm cov ntawv sib raug (a и b).

Tsis tu ncua hexagonal pyramid

• Lub hauv paus yog ib txwm hexagon ABCDEF.
• Lub ntsej muag sab yog sib npaug isosceles daim duab peb sab: AGB, BGC, CGD, DGE, EGF и FGA.
• Projection vertices G ntawm lub hauv paus - point O, yog qhov sib tshuam ntawm kab pheeb ces kaum / bisectors ntawm lub hexagon ABCDEF.
• GO yog qhov siab ntawm lub pyramid.
• GN - apothem (yuav tsum muaj rau hauv tag nrho).

Cov khoom ntawm lub pyramid tsis tu ncua

1. Txhua sab ntug ntawm daim duab yog sib npaug. Hauv lwm lo lus, sab saum toj ntawm lub pyramid yog nyob rau tib qhov deb ntawm txhua lub ces kaum ntawm nws lub hauv paus.
2. Lub kaum sab xis ntawm txhua sab tav thiab lub hauv paus yog tib yam.
3. Txhua lub ntsej muag yog inclined rau lub hauv paus ntawm tib lub kaum sab xis.
4. Cov cheeb tsam ntawm txhua sab ntsej muag yog sib npaug.
5. Tag nrho cov apothems yog sib npaug.
6. Nyob ib ncig ntawm lub pyramid tuaj yeem piav qhia, qhov chaw nruab nrab ntawm qhov yuav yog qhov kev sib tshuam ntawm cov perpendiculars kos mus rau qhov nruab nrab ntawm cov npoo.
7. Ib tug kheej kheej tuaj yeem sau rau hauv lub pyramid, qhov chaw uas yuav yog qhov kev sib tshuam ntawm cov bisectors, pib ntawm cov ces kaum ntawm sab ntug thiab lub hauv paus ntawm daim duab.

Nco ntsoov: Cov qauv rau kev nrhiav, nrog rau cov pyramids, tau nthuav tawm hauv cov ntawv tshaj tawm.