Altitude vs Median
Altitude thiab nruab nrab yog ob qhov siab siv thaum tham txog geometry ntawm daim duab peb sab.
Altitudes ntawm daim duab peb sab
Qhov siab ntawm daim duab peb sab yog ib txoj kab ntu txuas mus rau ib sab thiab dhau los ntawm vertex tawm tsam sab. Txij li daim duab peb sab muaj 3 sab, lawv txhua tus muaj qhov siab qhov siab ib sab muab tag nrho ntawm 3 qhov siab ntawm ib daim duab peb sab. Sab uas qhov siab yog perpendicular yog lub hauv paus txuas ntxiv ntawm qhov siab.
Altitude feem ntau txhais los ntawm tsab ntawv h (raws li qhov siab).
Altitudes tshwj xeeb yog siv los suav cov cheeb tsam ntawm daim duab peb sab. Qhov chaw ntawm daim duab peb sab yog ib nrab ntawm qhov siab thiab nws lub hauv paus.
Area=1/2 altitude×base=1/2 h×b
Tsis tas li ntawd, lub ntsiab lus ntawm kev sib tshuam ntawm peb qhov siab ntawm ob sab yog hu ua orthocenter. Lub orthocenter nyob hauv daim duab peb sab yog thiab tsuas yog tias daim duab peb sab yog daim duab peb sab mob.
Medians ntawm daim duab peb sab
Ib qho nruab nrab yog ib feem ntawm txoj kab hla nruab nrab ntawm ib sab thiab lub vertex tawm tsam sab ntawd. Qhov nruab nrab bisects lub kaum sab xis ntawm lub vertex. Nws kuj faib thaj tsam ntawm daim duab peb sab hauv ib nrab. Ib yam li qhov siab, muaj qhov nruab nrab tshwj xeeb rau txhua sab; yog li ntawd txhua daim duab peb sab muaj peb qhov nruab nrab. Tag nrho peb tus neeg nruab nrab ua ke faib daim duab peb sab ua rau rau daim duab peb sab me me nrog thaj tsam tib yam. (Saib daim duab)
Peb qhov nruab nrab ntawm daim duab peb sab sib tshuam ntawm ib qho taw tes, uas faib txhua qhov nruab nrab rau 2: 1 piv. Nws yog lub npe hu ua centroid ntawm daim duab peb sab thiab, rau ib tug niaj hnub laminar daim duab peb sab qhov chaw ntawm loj nyob ntawm no.
Ob lub orthocenter thiab qhov nruab nrab ntawm kev dag ntawm Euler kab, uas kuj muaj qhov ncig ntawm daim duab peb sab.
Qhov txawv ntawm qhov siab thiab qhov nruab nrab yog dab tsi?
• Ob qhov siab thiab qhov nruab nrab dhau los ntawm lub vertex, tab sis qhov siab dhau los ntawm qhov tsis sib haum ntawm cov ces kaum sab xis; i.e. perpendicular mus rau sab, thaum nruab nrab hla dhau ntawm qhov nruab nrab ntawm qhov tawm tsam.
• Qhov siab yog siv los xam thaj tsam ntawm daim duab peb sab.
• Ib qho nruab nrab faib thaj tsam ntawm daim duab peb sab hauv ib nrab thiab tag nrho peb faib daim duab peb sab ua rau rau daim duab peb sab me me nrog thaj tsam sib npaug.
• Cov neeg nruab nrab cuam tshuam ntawm qhov nruab nrab, thaum qhov siab sib tshuam ntawm lub orthocenter.
• Lub orthocenter yuav nyob sab hauv lossis sab nraum thaj tsam ntawm daim duab peb sab, tab sis centroid ib txwm nyob hauv thaj tsam ntawm daim duab peb sab.
