Video: Puas yog cov kaum sab xis ntawm lub isosceles trapezoid congruent?
2024 Tus sau: Miles Stephen | [email protected]. Kawg hloov kho: 2023-12-15 23:36
Base (sab saum toj thiab hauv qab) ntawm ib isosceles trapezoid yog thaum uas tig mus. Sab nraud ntawm ib qho isosceles trapezoid yog tib qhov ntev ( kev sib haum xeeb ). Cov lub kaum sab xis ntawm ob sab ntawm lub hauv paus yog tib qhov loj / ntsuas ( kev sib haum xeeb ).
Ib yam li ntawd, cov kaum sab xis ntawm daim duab peb sab isosceles puas sib haum?
Cov Lub kaum sab xis ntawm daim duab peb sab isosceles yog cov lub kaum sab xis tsim los ntawm cov puag thiab ib ceg ntawm lub daim duab peb sab . Cov puag cov ces kaum theorem converse hais tias yog ob lub kaum sab xis hauv a daim duab peb sab yog kev sib haum xeeb , ces ob sab opposite cov lub kaum sab xis kuj yog kev sib haum xeeb.
Tom qab, lo lus nug yog, dab tsi yog lub hauv paus kaum ntawm lub trapezoid? Ib khub ntawm lub kaum sab xis uas share tib yam puag hu ua puag cov ces kaum ntawm trapezoid . Hauv daim duab 1, ∠ A thiab ∠ B lossis ∠ C thiab ∠ D yog puag cov ces kaum ntawm trapezoid ABCD. Ob qhov tshwj xeeb ntawm cov isosceles trapezoid tuaj yeem ua pov thawj. Txoj Cai 53: Cov kaum sab xis ntawm ib qho isosceles trapezoid sib npaug.
Tib neeg kuj nug, dab tsi yog lub hauv paus kaum ntawm lub isosceles trapezoid?
Cov puag cov ces kaum ( lub kaum sab xis tsim ntawm cov uas tsis yog-parallel sab thiab parallel sab) yog sib npaug hauv ib isosceles trapezoid . Diagonals ntawm ib isosceles trapezoid yog sib npaug ntawm qhov ntev. Qhov sum ntawm opposite lub kaum sab xis hauv ib isosceles trapezoid yog 180 degrees.
Puas yog ob txhais ceg ntawm lub trapezoid sib haum?
THEOREM: Yog hais tias ib tug plaub fab (nrog ib txheej ntawm parallel sab) yog ib qho isosceles trapezoid , nws ob txhais ceg yog kev sib haum xeeb . THEOREM: (converse) Yog a trapezoid muaj sib ceg ceg , nws yog isosceles trapezoid.
Pom zoo:
Yuav ua li cas koj pom cov kaum sab xis ntawm lub isosceles trapezoid?
Lub hauv paus (sab saum toj thiab hauv qab) ntawm isoscelestrapezoid yog sib npaug. Cov sab nraud ntawm ib qho isoscelestrapezoid yog tib qhov ntev (congruent). Cov ces kaum ib sab ntawm lub hauv paus yog tib qhov loj / ntsuas (congruent)
Cov kab lus hloov sab hauv cov ces kaum piav qhia txoj haujlwm ntawm ob lub kaum sab xis li cas?
Hloov sab hauv cov ces kaum yog tsim los ntawm ib tug transversal intersecting ob parallel kab. Lawv nyob nruab nrab ntawm ob qho tib si kab tab sis nyob rau sab nraud ntawm lub transversal, tsim ob khub (plaub tag nrho cov ces kaum) ntawm cov ces kaum sab hauv. Hloov cov ces kaum sab hauv yog congruent, txhais tau tias lawv muaj qhov sib npaug
Puas yog cov kaum sab xis hauv ib daim duab peb sab isosceles ib txwm ntsuas 45?
Hauv ib daim duab peb sab isosceles, qhov sib npaug sab ua rau lub kaum sab xis. Nco ntsoov tias vim txoj cai daim duab peb sab yog isosceles, ces cov ces kaum ntawm lub hauv paus yog sib npaug. (Theorem 3.) Yog li ntawd txhua lub kaum sab xis yog 45 °
Dab tsi yog kev sib raug zoo ntawm sab nrauv thiab sab hauv lub kaum sab xis ntawm daim duab peb sab?
Cov kaum sab hauv yog hu ua Sab hauv cov ces kaum. Cov lej ntawm cov kaum sab hauv ntawm daim duab peb sab yog ib txwm 180 degrees. Lub kaum sab nrauv yog lub kaum sab xis ntawm ib sab ntawm ib qho duab, thiab ib txoj kab txuas ntxiv los ntawm sab tom ntej. Qhov sib npaug ntawm lub kaum sab nrauv thiab nws lub kaum sab hauv uas nyob ib sab kuj yog 180 degrees
Puas yog daim duab peb sab isosceles muaj ob lub kaum sab xis?
Thaum ib daim duab peb sab muaj ob sab congruent nws hu ua daim duab peb sab isosceles. Lub kaum sab xis ntawm ob sab ntawm tib qhov ntev yog congruent. Ib daim duab peb sab uas tsis muaj ib sab lossis cov kaum sab xis yog hu ua daim duab peb sab scalene