Ib lub duab plaub yog plaub fab plaub fab uas ob sab yog tib qhov ntev, ob sab yog tib qhov dav, thiab muaj plaub lub kaum sab xis. Txhawm rau nrhiav thaj tsam ntawm ib lub duab plaub peb yooj yim muab qhov ntev los ntawm qhov dav. Txhawm rau paub nrhiav thaj tsam ntawm lub duab plaub, ua raws cov kauj ruam yooj yim no.
Kauj ruam
Txoj Kev 1 ntawm 3: Nkag Siab Txog Plaub Hlis Plaub Hlis Ntuj
Kauj Ruam 1. Nkag siab txog lub duab plaub
Ib lub duab plaub yog plaub fab plaub hau, uas txhais tau tias nws muaj plaub sab. Ob sab sib thooj yog tib qhov ntev thiab dav. Yog hais tias ib sab ntawm lub duab plaub yog 10 piv txwv, tom qab ntawd qhov ntev ntawm sab nraud kuj yog 10.
Txhua lub xwmfab yog duab plaub, tabsis tsis yog txhua lub duab plaub yog plaub fab. Yog li kho ib lub xwmfab zoo li lub duab plaub hais txog kev nrhiav thaj chaw
Kauj Ruam 2. Paub cov mis rau nrhiav thaj tsam ntawm daim duab plaub
Cov mis rau nrhiav thaj tsam ntawm ib lub duab plaub yog A = L * W. Qhov no txhais tau tias thaj tsam ntawm lub duab plaub sib npaug rau qhov ntev lub sij hawm dav.
Txoj Kev 2 ntawm 3: Nrhiav thaj tsam ntawm lub duab plaub
Kauj Ruam 1. Nrhiav qhov ntev ntawm lub duab plaub
Cov lus nug feem ntau yuav muab sijhawm rau koj, tab sis yog tias koj tsis paub qhov ntev, tsuas yog siv tus pas ntsuas.
Nco ntsoov tias ob npaug hash nyob rau sab ntev ntawm lub duab plaub txhais tau tias ob sab yog tib qhov ntev
Kauj Ruam 2. Nrhiav qhov dav ntawm lub duab plaub
Siv tib txoj kev los nrhiav nws.
Nco ntsoov tias ib qho hash ntawm sab dav ntawm ib lub duab plaub txhais tau tias ob sab yog tib qhov dav
Kauj Ruam 3. Sau qhov ntev thiab dav ib sab
Hauv qhov piv txwv no, qhov ntev yog 5 cm thiab qhov dav yog 4 cm.
Kauj Ruam 4. Muab qhov ntev sib npaug rau qhov dav
Qhov ntev yog 5 cm thiab qhov dav yog 4 cm, ntsaws rau hauv Formula A = L * W txhawm rau nrhiav thaj chaw.
- A = 4cm * 5cm
- A = 20 cm^2 ib
Kauj Ruam 5. Qhia cov lus teb hauv cov chav nyob
Cov lus teb kawg yog 20 cm^2, uas nyeem "nees nkaum centimeters sib npaug."
Cov lus teb zaum kawg tuaj yeem sau ua ob txoj hauv kev: 20 cm.sq. los yog 20 cm^2
Txoj Kev 3 ntawm 3: Nrhiav thaj tsam yog tias Qhov Ntev ntawm Ib Sab thiab Kab Kab Ntsig paub
Kauj Ruam 1. Nkag Siab Pythagorean Theorem
Pythagorean theorem yog tus qauv rau kev nrhiav sab peb ntawm daim duab peb sab yog tias qhov txiaj ntsig ntawm ob tog tau paub. Peb tuaj yeem siv cov mis no los nrhiav qhov hypotenuse ntawm daim duab peb sab uas yog sab ntev tshaj plaws, lossis qhov ntev lossis dav uas ua tau raws lub kaum sab xis.
- Txij li cov duab plaub tau ua los ntawm plaub txoj cai kaum, kab pheeb ces kaum uas txiav los ntawm cov duab yuav tsim ib daim duab peb sab xis, yog li peb tuaj yeem siv Pythagorean theorem.
- Cov mis yog: a^2 + b^2 = c^2, a thiab b yog ob sab ntawm daim duab peb sab thiab c yog qhov hypotenuse lossis ntev tshaj plaws.
Kauj Ruam 2. Siv Pythagorean theorem los xam lwm sab ntawm daim duab peb sab
Cia peb hais ib lub duab plaub muaj ib sab ntawm 6 cm thiab kab pheeb ces kaum ntawm 10 cm. Nkag mus rau 6 cm rau ib sab, siv b rau lwm sab, thiab sau 10 cm raws li hypotenuse. Tam sim no yooj yim ntsaws qhov paub ntau npaum li cas rau hauv Pythagorean theorem. Nov yog li cas:
-
Ex:
6^2 + b^2 = 10^2
- 36 + b^2 = 100
- b^2 = 100 - 36
- b^2 = 64
- cag cag (b) = cag cag (64)
-
ib = 8
Qhov ntev ntawm lwm sab ntawm daim duab peb sab, uas tseem yog lwm sab ntawm daim duab plaub, yog 8 cm
Kauj Ruam 3. Muab qhov ntev sib npaug rau qhov dav
Tom qab siv Pythagorean theorem txhawm rau nrhiav qhov ntev thiab dav ntawm ib lub duab plaub, txhua yam koj yuav tsum tau ua yog muab nws sib npaug.
-
Ex:
6cm * 8cm = 48cm^2
Kauj Ruam 4. Qhia cov lus teb hauv cov chav nyob
Cov lus teb zaum kawg yog 48 cm^2, lossis 48 cm. ua sq.
Lub tswv yim
- Txhua lub xwmfab yog duab plaub. Txawm li cas los xij, tsis yog txhua lub duab plaub yog plaub fab.
- Cov lus teb rau thaj tsam ib txwm hais txog ntawm ib lub xwmfab.
