Txoj Kev 16.8: Yog cov kab pheeb ces kaum ntawm cov kab pheeb ces kaum yog congruent thiab perpendicular, lub parallelogram yog square.
Puas yog parallelogram puas yog square?
A square is a parallelogram Qhov no yeej muaj tseeb. Squares yog quadrilaterals nrog 4 congruent sab thiab 4 txoj cai ces kaum, thiab lawv kuj muaj ob pawg ntawm parallel sab. … Txij li cov squares yuav tsum yog plaub plaub fab nrog ob pawg ntawm cov kab sib txuas, ces tag nrho cov squares yog parallelograms.
Yuav ua li cas yuav tsum tau ua rau lub parallelogram ua ib square?
Yog tias lub plaub fab muaj plaub sab sib dhos thiab plaub lub kaum sab xis, ces nws yog square (rov qab ntawm lub ntsiab lus square). Yog hais tias ob sab sib law liag ntawm ib daim duab plaub yog congruent, ces nws yog ib tug square (tsis yog tus rov qab ntawm lub ntsiab txhais los yog converse ntawm ib tug khoom).
Thaum twg muaj peev xwm ua tau ib qho parallelogram hu ua ib daim duab plaub?
Yog parallelogram paub tias muaj ib lub kaum sab xis, ces rov siv cov kaum sab hauv sab hauv ua pov thawj tias tag nrho nws cov kaum sab xis yog kaum sab xis. Yog hais tias ib lub kaum sab xis ntawm lub parallelogram yog lub kaum sab xis, ces nws yog ib daim duab plaub.
Puas yog daim duab plaub ib lub parallelogram yog?
Vim tias nws muaj ob pawg ntawm cov kab sib dhos thiab ob khub ntawm cov lus rov qab 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. Txawm li cas los xij, tus parallelogram tsis yog ib daim duab plaub.
