txheem
Hauv kev tshaj tawm no, peb yuav txiav txim siab txog cov yam ntxwv ntawm qhov siab hauv qhov sib npaug (tsis tu ncua) daim duab peb sab. Peb tseem yuav tshuaj xyuas ib qho piv txwv ntawm kev daws teeb meem ntawm lub ncauj lus no.
Nco ntsoov: daim duab peb sab hu ua Vaj Huam Sib Luagyog tias tag nrho nws sab yog sib npaug.
Qhov siab cov khoom hauv ib daim duab peb sab sib npaug
Khoom Muaj Khoom 1
Txhua qhov siab nyob rau hauv daim duab peb sab sib npaug yog ob qho tib si bisector, nruab nrab, thiab ib qho perpendicular bisector.
- BD - qhov siab qis rau sab AC;
- BD yog qhov nruab nrab uas faib sab AC hauv ib nrab, ie AD = DC;
- BD - lub kaum sab xis bisector ABC, ie ∠ABD = ∠CBD;
- BD yog qhov nruab nrab perpendicular rau AC.
Khoom Muaj Khoom 2
Tag nrho peb qhov siab nyob rau hauv ib daim duab peb sab sib npaug muaj qhov ntev.
AB = CF
Khoom Muaj Khoom 3
Qhov siab nyob rau hauv ib daim duab peb sab sib npaug ntawm lub orthocenter (taw tes ntawm kev sib tshuam) muab faib rau hauv qhov sib piv ntawm 2: 1, suav los ntawm lub vertex uas lawv tau kos.
- AO = 2 AO
- OB = 2 OD
- CO = 2
Khoom Muaj Khoom 4
Lub orthocenter ntawm daim duab peb sab sib npaug yog qhov nruab nrab ntawm cov ntawv sau thiab cov voj voog ncig.
- R yog lub vojvoog ntawm lub voj voog ncig;
- r yog lub vojvoog ntawm lub voj voog inscribed;
- R = 2 r (ua raws los ntawm Cov khoom 3).
Khoom Muaj Khoom 5
Qhov siab nyob rau hauv ib daim duab peb sab sib npaug faib nws mus rau hauv ob qhov sib npaug ntawm thaj tsam (equal-area) txoj cai-angled daim duab peb sab.
S1 =S2
Peb qhov siab nyob rau hauv ib daim duab peb sab sib npaug muab faib ua 6 txoj cai daim duab peb sab ntawm qhov sib npaug.
Khoom Muaj Khoom 6
Paub qhov ntev ntawm sab ntawm daim duab peb sab sib npaug, nws qhov siab tuaj yeem xam los ntawm tus qauv:
a yog sab ntawm daim duab peb sab.
Piv txwv ntawm qhov teeb meem
Lub vojvoog ntawm lub voj voog ncig ib ncig ntawm daim duab peb sab sib npaug yog 7 cm. Nrhiav sab ntawm daim duab peb sab no.
tshuaj
Raws li peb paub los ntawm khoom 3 и 4, lub vojvoog ntawm lub voj voog ncig yog 2/3 ntawm qhov siab ntawm daim duab peb sab sib npaug (h). Yog li ntawd, h Luas = 7 ∶ 2 ⋅ 3 = 10,5 cm.
Tam sim no nws tseem yuav suav qhov ntev ntawm sab ntawm daim duab peb sab (qhov qhia tau muab los ntawm cov qauv hauv Khoom Muaj Khoom 6):