Thawj, kab laug sab tsis tas ib txwm zoo sib xws. … Nyob rau hauv ob qho tib si, ceg ntawm daim duab peb sab loj yog ob zaug ntev npaum li cov ceg sib thooj hauv daim duab peb sab me. Muab hais tias lub kaum sab xis ntawm ob txhais ceg yog lub kaum sab xis nyob rau hauv txhua daim duab peb sab, cov ces kaum yog congruent.
Puas yog ob daim duab peb sab ib txwm ib yam?
Yog, ob txoj cai isosceles daim duab peb sab ib txwm zoo sib xws. Txhawm rau ua pov thawj vim li cas qhov no yog qhov teeb meem, peb tuaj yeem txiav txim siab tias lub kaum sab xis ntawm ib daim duab peb sab isosceles yog 45 °, 45 °, thiab 90 °. Txhawm rau ua qhov no, peb siv cov theorems thiab cov khoom hauv qab no: Cov txiaj ntsig ntawm lub kaum sab xis ntawm daim duab peb sab yog 180 °.
Puas yog daim duab peb sab zoo ib yam?
Yog tias ob khub ntawm cov ces kaum sib thooj hauv ib khub ntawm daim duab peb sab yog congruent, ces daim duab peb sab zoo ib yam. 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. … Tab sis thaum lawv txav mus, daim duab peb sab lawv tsim ib txwm khaws nws cov duab. Yog li, lawv ib txwm tsim cov duab peb sab zoo sib xws.
Koj tuaj yeem qhia tau li cas yog tias ob daim duab peb sab zoo sib xws?
Ob daim duab peb sab hais tias zoo ib yam yog tias lawv cov kaum sib raug zoo sib xws thiab cov sab sib raug zoo sib npaug. Hauv lwm lo lus, cov duab peb sab zoo sib xws yog tib yam, tab sis tsis tas yuav tsum muaj qhov loj me. Daim duab peb sab yog congruent yog tias, ntxiv rau qhov no, lawv cov sab sib txuas yog sib npaug ntev.
txhais li cas yogob daim duab peb sab zoo ib yam?
Ob daim duab peb sab zoo ib yam yog tias lawv ua tau raws li ib qho ntawm cov qauv hauv qab no.: Ob khub ntawm cov ces kaum sib npaug.: Peb khub ntawm qhov sib thooj yog proportional.: Ob khub ntawm cov sab sib raug yog proportional thiab cov ces kaum ntawm lawv sib npaug.
