Video: Koj ua pov thawj li cas ntawm cov ces kaum sab nrauv ntawm daim duab peb sab yog 360?
2024 Tus sau: Miles Stephen | [email protected]. Kawg hloov kho: 2023-12-15 23:36
Ib sab nrauv lub kaum sab xis ntawm ib daim duab peb sab yog sib npaug rau cov sum ntawm qhov opposite sab hauv cov ces kaum . Yog xav paub ntxiv txog qhov no saib Daim duab peb sab sab nraud theorem. Yog sib npaug lub kaum sab xis yog coj ntawm txhua vertex, lub sab nrauv cov ces kaum ib txwm ntxiv rau 360 ° Qhov tseeb, qhov no muaj tseeb rau txhua qhov convex polygon, tsis yog daim duab peb sab.
Ib yam li ntawd, nws raug nug, koj ua li cas ua pov thawj cov kaum sab nrauv ntawm daim duab peb sab?
Sab nrauv lub kaum sab xis ntawm daim duab peb sab Theorem Theorem 2: Yog ib sab ntawm a daim duab peb sab yog ncua, ces tus sab nrauv lub kaum sab xis yog li tsim yog cov sum ntawm ob opposite sab hauv lub kaum sab xis ntawm daim duab peb sab . Hauv daim duab muab, sab BC ntawm ∆ABC txuas ntxiv.
Ib yam li ntawd, koj yuav ua li cas thiaj nrhiav tau qhov sib npaug ntawm cov ces kaum sab nrauv? Cov sum ntawm sab nrauv cov ces kaum ntawm ib tug tsis tu ncua polygon yuav ib txwm sib npaug 360 degrees. Rau nrhiav tus nqi ntawm ib tug muab sab nrauv lub kaum sab xis ntawm ib tug tsis tu ncua polygon, tsuas yog faib 360 los ntawm tus naj npawb ntawm sab los yog lub kaum sab xis uas lub polygon muaj.
Ib yam li ntawd, koj tuaj yeem nug, dab tsi yog qhov txiaj ntsig ntawm 3 sab nrauv lub kaum sab xis ntawm daim duab peb sab?
Ib qho tuaj yeem txiav txim siab qhov suav ntawm tag nrho peb lub kaum sab nrauv, uas sib npaug rau 360 ° hauv Euclidean rooj plaub (raws li rau txhua qhov convex. polygon ), yog tsawg dua 360 ° nyob rau hauv cov ntaub ntawv kheej kheej, thiab ntau dua 360 ° nyob rau hauv cov ntaub ntawv hyperbolic.
Puas tag nrho cov ces kaum hauv daim duab peb sab ntxiv txog 360?
Txij li thaum daim duab peb sab yog congruent txhua daim duab peb sab muaj ib nrab li ntau degrees, namely 180. Yog li no yog muaj tseeb rau txhua txoj cai daim duab peb sab . Tab sis yog koj saib ob txoj cai lub kaum sab xis uas ntxiv rau 180 degrees ces lwm yam lub kaum sab xis , cov lub kaum sab xis ntawm tus thawj daim duab peb sab , ntxiv mus txog 360 - 180 = 180 °.
Pom zoo:
Cov kab lus hloov sab hauv cov ces kaum piav qhia txoj haujlwm ntawm ob lub kaum sab xis li cas?
Hloov sab hauv cov ces kaum yog tsim los ntawm ib tug transversal intersecting ob parallel kab. Lawv nyob nruab nrab ntawm ob qho tib si kab tab sis nyob rau sab nraud ntawm lub transversal, tsim ob khub (plaub tag nrho cov ces kaum) ntawm cov ces kaum sab hauv. Hloov cov ces kaum sab hauv yog congruent, txhais tau tias lawv muaj qhov sib npaug
Koj tuaj yeem ua pov thawj li cas 2 daim duab peb sab zoo sib xws siv lub kaum sab xis sab SAS zoo sib xws postulate?
SAS Similarity Theorem hais tias yog ob sab hauv ib daim duab peb sab yog proportional rau ob sab hauv lwm daim duab peb sab thiab lub kaum sab xis nyob rau hauv ob qho tib si congruent, ces ob daim duab peb sab zoo ib yam. Ib qho kev hloov pauv zoo sib xws yog ib lossis ntau qhov kev hloov pauv tsis tu ncua ua raws li kev dilation
Vim li cas nws thiaj li hais tias lub Orthocenter ntawm daim duab peb sab obtuse yuav tsum nyob rau sab nraud ntawm daim duab peb sab?
Nws hloov tawm tias tag nrho peb qhov siab ib txwm sib tshuam ntawm tib lub ntsiab lus - lub npe hu ua orthocenter ntawm daim duab peb sab. Lub orthocenter tsis yog ib txwm nyob hauv daim duab peb sab. Yog tias daim duab peb sab yog obtuse, nws yuav nyob sab nraud. Txhawm rau ua kom qhov no tshwm sim cov kab qhov siab yuav tsum tau txuas ntxiv kom lawv hla
Koj ua pov thawj tias daim duab peb sab zoo li cas?
Yog hais tias ob khub ntawm cov ces kaum sib xws nyob rau hauv ib khub ntawm daim duab peb sab yog congruent, ces daim duab peb sab yog zoo sib xws. Peb paub qhov no vim yog tias ob lub kaum sab xis yog tib yam, ces tus khub thib peb kuj yuav tsum sib npaug. Thaum peb lub kaum sab xis yog txhua qhov sib npaug, peb khub ntawm sab yuav tsum tau sib npaug
Dab tsi yog kev sib raug zoo ntawm sab nrauv thiab sab hauv lub kaum sab xis ntawm daim duab peb sab?
Cov kaum sab hauv yog hu ua Sab hauv cov ces kaum. Cov lej ntawm cov kaum sab hauv ntawm daim duab peb sab yog ib txwm 180 degrees. Lub kaum sab nrauv yog lub kaum sab xis ntawm ib sab ntawm ib qho duab, thiab ib txoj kab txuas ntxiv los ntawm sab tom ntej. Qhov sib npaug ntawm lub kaum sab nrauv thiab nws lub kaum sab hauv uas nyob ib sab kuj yog 180 degrees