txheem
Hauv kev tshaj tawm no, peb yuav xav txog cov ntsiab lus thiab cov khoom tseem ceeb ntawm isosceles trapezoid.
Nco qab tias lub trapezoid hu ua isosceles (los yog isosceles) yog tias nws ob sab sib npaug, piv txwv li AB = CD.
Khoom Muaj Khoom 1
Lub kaum sab xis ntawm ib qho ntawm lub hauv paus ntawm lub isosceles trapezoid yog sib npaug.
- ∠DAB = ∠ADC = a
- ∠ABC = ∠DCB = b
Khoom Muaj Khoom 2
Qhov sib npaug ntawm cov kaum sab xis ntawm lub trapezoid yog 180 °.
Rau daim duab saum toj no: α + β = 180°.
Khoom Muaj Khoom 3
Cov kab pheeb ces kaum ntawm lub isosceles trapezoid muaj tib qhov ntev.
AB = BD = d
Khoom Muaj Khoom 4
Qhov siab ntawm lub isosceles trapezoid BEqis dua ntawm lub hauv paus ntawm qhov ntev dua AD, muab faib ua ob ntu: thawj yog sib npaug rau ib nrab ntawm cov lej ntawm cov hauv paus, qhov thib ob yog ib nrab ntawm lawv qhov sib txawv.
Khoom Muaj Khoom 5
Kab ntu MNtxuas lub midpoints ntawm lub hauv paus ntawm lub isosceles trapezoid yog perpendicular rau cov hauv paus.
Txoj kab dhau los ntawm qhov nruab nrab ntawm lub hauv paus ntawm isosceles trapezoid yog hu ua nws axis ntawm symmetry.
Khoom Muaj Khoom 6
Ib lub voj voog tuaj yeem hla ib ncig ntawm txhua lub isosceles trapezoid.
Khoom Muaj Khoom 7
Yog tias cov lej ntawm lub hauv paus ntawm lub isosceles trapezoid yog sib npaug rau ob zaug ntawm qhov ntev ntawm nws sab, ces lub voj voog tuaj yeem sau rau hauv nws.
Lub vojvoog ntawm xws li ib lub voj voog yog sib npaug rau ib nrab ntawm qhov siab ntawm lub trapezoid, piv txwv li R = h/2.
Nco ntsoov: tus so ntawm cov khoom siv rau txhua hom trapezoids tau muab rau hauv peb cov ntawv tshaj tawm -.