Obtuse kaum: hauj lwm thiab cov yam ntxwv

Daim duab peb sab - ib tug duab daim duab muaj peb interconnected kab ntsiab lus uas tsis dag rau ib tug kab xwb nyob rau hauv lub dav hlau. Lub vertices ntawm daim duab peb sab - lub taw tes rau lub hauv paus ntawm lub ces kaum, thiab cov kab sib txuas rau lawv, hu ua lub sab ntawm daim duab peb sab. Yuav kom txiav txim seb lub cheeb tsam ntawm ib daim duab, ntau zaus siv cov daim duab peb sab sab hauv qhov chaw.

kev faib

Dhau li cov vajvoos peb sab nrog teej sab, muaj ceskaum, piv txwv li, muaj ob tug zoo tib sab. Lawv hu ua sab, thiab lwm sab - puag daim duab. Yog lwm hom uas - equilateral. Tag nrho peb ntawm lawv sab yog muaj sib npaug zos ntev.

Rau cov vajvoos peb sab xam qhovkev degree ntsuas system. Cov nuj nqis tej zaum yuav muaj ces kaum sib txawv, yog li ntawd lawv dej num raws li nram no:

• Lub - muaj ib tug kaum sab xis ntawm 90 degrees. Lub ob sab uas nyob ib sab mus rau lub ces kaum, hu ua ob txhais ceg, thiab lub thib peb - cov hypotenuse;
• Ntse-edged - ib tug peb tog, muaj tag nrho cov ntse ces kaum tsis tshaj 90 degrees;
• Obtuse - ib lub ntau dua 90 degrees.

Lus Txhais thiab tsis ntawm daim duab peb sab

Raws li twb tau sau tseg, daim duab peb sab - yog ib hom ntawm polygon muaj peb vertices thiab tib ncaj, lawv koom. Qhia cov kab yog feem ntau yog cov tib: lub ces kaum - me me Latin cov tsiaj ntawv, thiab cov lus rov sab ntawm txhua - sib nug xov mus rau ib tug capital tsab ntawv.

Yog hais tias koj ntxiv mus rau tag nrho cov ces kaum ntawm ib tug peb tog, nws yuav npaum li cas los 180 degrees. Yuav kom paub qhov puab ces kaum ntawm qhov yuav tsum tau 180 degrees rho lub qhov ntau ntawm cov sab nraud kaum sab xis ntawm daim duab peb sab. Nyob rau hauv thiaj li yuav nrhiav tau tawm yog dab tsi yog sib npaug zos rau lub kaum sab xis uas yog sab nraud, nws yog tsim nyog los ntxiv ob cais nws los ntawm lub kaum sab xis ntawm lub sab hauv.

Txhua daim duab peb sab muaj nws mob los yog obtuse kaum, yam txawv lub loj lub yog lub loj tshaj sab. Yog hais tias ncaj nruab nrab ntawm cov vertices yog tib yam, ntsig txog, thiab txhua lub kaum sab xis yog 60 degrees.

obtuse daim duab peb sab

Obtuse kaum sab xis ntawm ib tug peb tog yog yeej ib txwm siab tshaj ib tug 90 degree angle, tab sis me me-scale. Yog li, lub obtuse angle yog los ntawm 90 mus rau 180 degrees.

Cov lus nug tshwm sim seb puas muaj yog ntau tshaj ib tug obtuse angle nyob rau hauv no daim duab? Cov lus teb lies nyob rau hauv qhov chaw: tsis muaj, vim hais tias cov sum ntawm cov ces kaum yuav tsum muaj tsawg tshaj li ⁰ 180. Yog hais tias ob ces kaum yuav tsum tau, rau cov piv txwv, nyob rau ntawm lub 95 degrees, peb tsuas muaj qhov chaw.

Ob tug obtuse polygon yog:

• Yog hais tias ob qho tag nrho yog muaj sib npaug thiab lub kaum sab xis ntawm lawv sab nyob therebetween;
• Yog hais tias ib sab thiab ob ces kaum uas yog tom ntej no mus rau nws, yog muaj sib npaug;
• Yog hais tias peb ob tog obtuse cov vajvoos peb sab yog muaj sib npaug.

Zoo tshaj plaws kab obtuse daim duab peb sab

Tag nrho cov vajvoos peb sab nrog obtuse ces kaum, muaj yog ib tug kab hu ua zoo kawg li. Tus thawj ntawm cov - rau qhov siab. Nws yog ib tug perpendicular los ntawm ib tug kab los sib ntsib rau nws coj sab. Tag nrho heights muaj txojkev ntawm lub taw tes, uas yog xa mus rau raws li lub orthocenter. Daim duab peb sab nrog lub obtuse kaum nws yuav sab nraum ntawm lub puab nws tus kheej. Raws li rau lub ntse fab, qhov chaw muaj nyob rau hauv daim duab peb sab.

Lwm kab - median. Qhov no yog txoj kab los ntawm cov nyiaj rau cov uas tsim nyog sab ntawm qhov chaw. Tag nrho cov pom zoo theem nrab nyob rau hauv ib tug daim duab peb sab, thiab muab lawv kawm tuab si lug - qhov chaw ntawm lub ntiajteb txawj nqus ntawm ib tug polygon.

Bisector - kab bisecting ob obtuse ces kaum, thiab lwm tus neeg. Cov kev tshuam ntawm cov peb kab yog ib txwm rooj plaub xwb nyob rau hauv cov duab thiab yog txhais raws li qhov chaw ntawm lub vajvoog inscribed nyob rau hauv ib tug daim duab peb sab.

Nyob rau hauv lem, qhov chaw ntawm lub vajvoog circumscribed txog cov nuj nqis yuav tsum tau los ntawm peb lub nruab nrab perpendiculars. Qhov no kab, uas tau tshuav tawm ntawm cov txhais tau tias ntawm cov kab ncaj nraim pub ntxiv tshaj qhov kab los sib ntsib. Qhov chaw sib tshuam ntawm peb nruab nrab perpendiculars ntawm ib tug peb tog muaj obtuse ces kaum, yog nyob sab nraum lub cev.