Lub kaum sab xis ntawm daim duab peb sab yog dab tsi? Rau lo lus nug no, ib tug paub zoo hais tias tawg tawm ntawm tus nplaig ntawm ib txhia neeg: "Qhov no yog ib tug nas khiav nyob ib ncig ntawm lub ces kaum thiab faib lub ces kaum ntawm ib nrab." Yog tias lo lus teb yuav tsum yog "nrog kev lom zem", ces tej zaum nws yog. Tab sis los ntawm qhov kev xav ntawm kev tshawb fawb, lo lus teb rau lo lus nug no yuav tsum tau ua ib yam dab tsi zoo li no: "Qhov no yog ib qho hluav taws xob pib ntawm lub ces kaum thiab faib cov tom kawg rau hauv ob qhov sib npaug." Nyob rau hauv geometry, daim duab no kuj pom tau tias yog ib ntu ntawm lub bisector kom txog thaum nws sib tshuam nrog rau sab nraud ntawm daim duab peb sab. Qhov no tsis yog ib qho kev xav yuam kev. Dab tsi ntxiv yog paub txog lub kaum sab xis bisector, dua li nws txhais?
Zoo li txhua qhov chaw ntawm cov ntsiab lus, nws muaj nws tus yam ntxwv. Thawj ntawm lawv yog qhov tsis yog ib qho kos npe, tab sis ib qho kev qhia uas tuaj yeem hais luv luv raws li hauv qab no: "Yog hais tias lub bisector faib tawm sab nraud rau hauv ob feem, ces lawv qhov piv yuav sib haum mus rau qhov sib piv ntawm ob sab ntawm qhov loj.daim duab peb sab".
Qhov khoom thib ob nws muaj: qhov kev sib tshuam ntawm cov bisectors ntawm txhua lub ces kaum yog hu ua incenter.
Thib peb kos npe: lub bisectors ntawm ib sab hauv thiab ob sab sab nraud ntawm ib daim duab peb sab sib tshuam ntawm qhov chaw ntawm ib qho ntawm peb lub voj voog inscribed hauv nws.
Plaub yam khoom ntawm lub kaum sab xis ntawm daim duab peb sab yog tias yog tias txhua tus sib npaug, ces qhov kawg yog isosceles.
Lub cim thib tsib tseem cuam tshuam txog daim duab peb sab isosceles thiab yog cov lus qhia tseem ceeb rau nws qhov kev lees paub hauv kev kos duab los ntawm bisectors, uas yog: hauv daim duab peb sab isosceles, nws ib txhij ua qhov nruab nrab thiab qhov siab.
Lub bisector ntawm lub kaum sab xis tuaj yeem tsim los ntawm kev siv lub compass thiab straightedge:
Txoj cai thib rau hais tias nws tsis tuaj yeem tsim ib daim duab peb sab siv tom kawg nkaus xwb nrog cov bisectors uas muaj, ib yam li nws tsis tuaj yeem tsim kom muaj ob npaug ntawm lub voos xwmfab, square ntawm lub voj voog thiab trisection ntawm lub kaum sab xis. nyob rau hauv no txoj kev. Hais lus nruj me ntsis, qhov no yog tag nrho cov khoom ntawm lub kaum sab xis ntawm daim duab peb sab.
Yog tias koj ua tib zoo nyeem cov kab lus dhau los, tej zaum koj xav tau ib kab lus. "Lub trisection ntawm lub kaum sab xis yog dab tsi?" - koj yeej yuav nug. Lub trisectrix zoo ib yam li bisector, tab sis yog tias koj kos lub tom kawg, ces lub kaum sab xis yuav muab faib ua ob qhov sib npaug, thiab thaum tsim ib qho trisection, rau hauvpeb. Lawm, lub bisector ntawm lub kaum sab xis yog yooj yim rau nco qab, vim hais tias lub trisection tsis qhia nyob rau hauv tsev kawm ntawv. Tab sis rau qhov ua tiav, kuv yuav qhia koj txog nws.
Ib lub trisector, raws li kuv tau hais, tsis tuaj yeem tsim tau tsuas yog nrog lub compass thiab tus pas ntsuas, tab sis nws tuaj yeem tsim tau siv Fujita txoj cai thiab qee qhov nkhaus: Pascal's snails, quadratrices, Nicomedes 'conchoids, conic sections, Archimedes 'spirals..
Teeb meem ntawm trisection ntawm lub kaum sab xis yog yooj yim daws tau siv nevsis.
Nyob rau hauv geometry muaj ib lub theorem txog lub kaum trisectors. Nws yog hu ua Morley (Morley) theorem. Nws hais tias cov ntsiab lus kev sib tshuam ntawm qhov nruab nrab trisectors ntawm txhua lub kaum sab xis yuav yog cov vertices ntawm daim duab peb sab sib npaug.
Ib daim duab peb sab dub me me hauv ib qho loj yuav ib txwm sib npaug. Qhov kev xav no tau tshawb pom los ntawm tus kws tshawb fawb Askiv Askiv Frank Morley hauv xyoo 1904.
Ntawm no yog txhua yam uas yuav tsum tau kawm txog kev faib lub kaum sab xis: lub trisector thiab bisector ntawm lub kaum sab xis ib txwm xav tau cov lus piav qhia ntxaws. Tab sis ntawm no muaj ntau lub ntsiab lus tau muab uas tseem tsis tau nthuav tawm los ntawm kuv: Pascal tus qwj, Nicomedes 'conchoid, thiab lwm yam. Tsis txhob yuam kev, tuaj yeem sau ntxiv txog lawv.
