Rau ib tug tsis tu ncua polygon, lub perimeter yog sib npaug rau cov khoom ntawm ib sab ntev thiab tus naj npawb ntawm sab ntawm lub polygon. Piv txwv li, lub perimeter ntawm ib txwm pentagon uas nws sab ntev 8 cm, yog muab los ntawm; luas=8 x 5=40 cm.
Dab tsi yog qhov ib puag ncig ntawm lub polygon?
Qhov ib puag ncig ntawm ib lub polygon txhais tau tias yog tus lej ntawm qhov ntev ntawm tus ciam teb ntawm lub polygon. Hauv lwm lo lus, peb hais tias tag nrho qhov kev ncua deb them los ntawm ob sab ntawm ib qho polygon muab nws thaj tsam.
Yuav ua li cas koj pom qhov ib puag ncig ntawm lub polygon ntawm daim duab?
Qhov ib puag ncig ntawm ib qho polygon yuav yog pom los ntawm kev ntxiv qhov ntev ntawm nws sab. Piv txwv li, yog tias koj muaj 6-sided polygon nrog sab uas yog 1 '', 3 '', 5 '', 4 '', 3'', thiab 2 '' ntev, koj yuav ntxiv cov lej. 1 + 3 + 5 + 4 + 3 + 2=18, yog li thaj tsam ntawm hexagon yuav yog 18 ntiv tes.
Dab tsi yog qhov ib puag ncig ntawm daim duab?
Lub ib puag ncig ntawm daim duab yog qhov kev ncua deb ntawm sab nraud ntawm daim duab. Qhov no muaj tseeb txawm hais tias daim duab yog ib daim duab paub zoo li lub duab plaub lossis daim duab peb sab, lossis yog tias nws yog ib daim duab nyuaj zoo li lub hauv paus ntawm lub tsev. Txhawm rau nrhiav thaj tsam ntawm daim duab no, koj yuav tsum ntxiv qhov ntev ntawm tag nrho 6 sab.
Dab tsi yog ib puag ncig hauv lej?
Qhov ib puag ncig ntawm ib daim duab yog qhov ntsuas tag nrho ntawm tag nrho cov npoo ntawm cov duabpiv txwv li. ibdaim duab peb sab muaj peb npoo, yog li nws qhov perimeter yog tag nrho ntawm peb cov npoo ntxiv ua ke. … Qhov ib puag ncig ntawm daim duab plaub tuaj yeem suav tau los ntawm kev ntxiv qhov ntev thiab qhov dav ua ke thiab ua ob npaug.
