Cov kab ntsug koom nrog cov kab uas nyob ib sab ntawm 90 ° cov ces kaum, uas txhais tau hais tias sab nraud ntawm cov duab plaub yog cov kab sib txuas. Txij li thaum nws muaj ob pawg ntawm cov kab sib txuas thiab ob khub ntawm cov lus sib dhos uas sib koom ua ke, ib daim duab plaub muaj tag nrho cov khoom ntawm ib qho parallelogram. Tias yog vim li cas ib daim duab plaub ib txwm yog parallelogram.
Puas yog daim duab plaub ib lub parallelogram muaj lossis tsis yog?
Parallelograms yog quadrilaterals nrog ob pawg ntawm kev sib luag. Txij li cov squares yuav tsum yog quadrilaterals nrog ob pawg ntawm qhov sib npaug, ces tag nrho cov squares yog parallelograms. 5. Ib qho piv txwv yog ib daim duab plaub.
Puas yog daim duab plaub yog ib qho parallelogram?
Ib daim duab plaub yog plaub plaub fab uas txhua lub kaum sab xis yog kaum sab xis. Ib daim duab plaub yog ib qho parallelogram, yog li nws sab nraud yog sib npaug. Cov kab pheeb ces kaum ntawm daim duab plaub yog sib npaug thiab sib npaug.
Koj ua pov thawj li cas tias daim duab plaub yog ib qho parallelogram?
Txhua daim duab plaub yog parallelograms. Yog tias tus parallelogram muaj (tsawg kawg) ib lub kaum sab xis, ces nws yog ib daim duab plaub. Yog hais tias lub quadrilateral muaj 2 khub ntawm opposite sab uas yog congruent, ces nws yog ib tug parallelogram. Yog hais tias cov kab pheeb ces kaum ntawm plaub plaub fab ob sab sib npaug, ces cov plaub fab yog ib qho parallelogram.
Yuav ua li cas koj thiaj paub yog tus parallelogram yog square?
Txoj Kev 16.8: Yog cov kab pheeb ces kaum ntawm cov kab pheeb ces kaum yog congruent thiab perpendicular, lub parallelogram yog square.
