Nrhiav thaj tsam ntawm ib yam khoom yog yooj yim heev tsuav koj nkag siab cov txuj ci thiab cov qauv siv. Yog tias koj muaj txoj kev paub zoo, koj tuaj yeem pom thaj chaw thiab thaj chaw ntawm ib yam khoom twg. Saib Kauj Ruam 1 hauv qab no kom pib.
Kauj ruam
Txoj Kev 1 ntawm 2: Xam Thaj Tsam Ntawm Ob Yam Khoom
Kauj Ruam 1. Txheeb xyuas qhov zoo ntawm cov khoom
Yog tias koj lub hom phiaj tsis yog lub ntsej muag uas pom tau yooj yim, xws li lub voj voos lossis lub trapezoid, tom qab ntawd koj cov khoom tuaj yeem ua los ntawm ntau yam duab. Koj yuav tsum paub cov duab uas tsim ua lub tsev loj.
Hauv qhov teeb meem no, lub hom phiaj muaj ob peb daim duab: ib daim duab peb sab, trapezoid, ib lub xwmfab, ib lub xwmfab, thiab ib lub vojvoog ib nrab
Kauj Ruam 2. Sau cov qauv kom pom thaj tsam ntawm txhua daim duab
Cov qauv no yuav tso cai rau koj siv qhov ntsuas paub ntawm txhua tus duab kom pom nws thaj chaw. Nov yog cov qauv rau nrhiav thaj tsam ntawm txhua qhov duab:
- Luas = Square2 = ib2
- Thaj tsam ntawm lub duab plaub = dav x siab = l x t
- Thaj tsam ntawm Trapezoid = [(sab 1 + sab 2) x qhov siab]/2 = [(a + b) x h]/2
- Cheeb tsam ntawm daim duab peb sab = puag x qhov siab x 1/2 = (a + t)/2
- Cheeb Tsam Ib Leeg = (π x voos kheej -kheej)2)/2 = (πx r2)/2
Kauj Ruam 3. Sau qhov ntev ntawm txhua tus duab
Tom qab koj sau cov qauv, sau qhov ntev ntawm txhua tus lej kom koj tuaj yeem nkag mus rau qhov muaj txiaj ntsig. Nov yog qhov ntev ntawm txhua qhov tsim:
- Luas: a = 2.5 cm
- Luas = l = 4.5 cm, t = 2.5 cm
- Trapezoid = a = 3 cm, b = 5 cm, t = 5 cm
- Daim duab peb sab = a = 3 cm, t = 2.5 cm
- Ib nrab = r = 1.5 cm
Kauj Ruam 4. Siv cov qauv thiab qhov ntev los nrhiav thaj tsam ntawm txhua yam khoom thiab ntxiv lawv
Los ntawm kev nrhiav thaj tsam ntawm txhua tus duab, koj tuaj yeem pom thaj tsam ntawm lub tsev uas tsim nws; Tom qab koj paub thaj tsam ntawm txhua lub tsev siv cov qauv thiab ntsuas ntsuas, txhua yam koj yuav tsum ua txhawm rau nrhiav thaj tsam ntawm tag nrho lub tsev yog ntxiv lawv. Thaum xam thaj tsam, koj yuav tsum nco ntsoov sau thaj tsam ntawd hauv cov duab plaub. Tag nrho thaj tsam ntawm lub tsev yog 44.78 cm2. Nov yog yuav xam nws li cas:
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Nrhiav thaj tsam ntawm txhua tus duab:
- Luas = 2.5 cm2 = 6.25 hli2
- Luas = 4.5 cm x 2.5 cm = 11.25 cm2
- Trapezoid = [(3 cm + 5 cm) x 5 cm]/2 = 20 cm2
- Daim duab peb sab = 3 cm x 2.5 cm x 1/2 = 3.75 cm2
- Ib nrab vajvoog = 1.5 cm2 x 1/2 x 3.53 cm2
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Ntxiv thaj tsam ntawm txhua tus duab:
- Thaj chaw ntawm cov khoom = thaj tsam ntawm square + cheeb tsam ntawm quad + cheeb tsam ntawm trapezoid + cheeb tsam ntawm daim duab peb sab + thaj tsam ntawm ib nrab lub voj voog
- Cheeb Tsam Ntawm Lub Cev = 6.25 cm2 + 11.25 cm kuv2 + 20 cm ib2 + 3.75 cm kuv2 + 3.53 cm kuv2
- Cheeb Tsam Ntawm Lub Cev = 44, 78 cm2
Txoj Kev 2 ntawm 2: Xam Xaj Nto Chaw ntawm 3-D Cov Hom Phiaj
Kauj Ruam 1. Sau cov qauv kom pom thaj tsam ntawm txhua daim duab
Qhov chaw saum npoo av yog thaj chaw tag nrho ntawm cov khoom siv. Txhua qhov khoom peb-seem muaj thaj tsam ib puag ncig; nws ntim yog qhov chaw nyob ntawm tus kwv. Nov yog cov qauv rau nrhiav thaj tsam ntawm ntau yam khoom:
- Lub cheeb tsam ntawm lub voos xwmfab = 6 x sab2 = 6 tsi2
- Lub khob hliav qab thaj tsam = x radius x ob + x radius2 = x r x s + r2
- Qhov cheeb tsam ntawm tus kheej = 4 x x radius2 = 4πr2
- Qhov cheeb tsam ntawm lub tog raj kheej = 2 x x radius2 + 2 x x radius x height = 2πr2 + 2 hli
- Cov cheeb tsam saum npoo ntawm lub xwmfab puag ncig = sab ntawm lub hauv paus2 + 2 x sab ntawm lub hauv paus x t = s2 + 2 ncu
Kauj Ruam 2. Sau qhov ntev ntawm txhua tus duab
Nov yog qhov ntev:
- Cube = sab = 3.5 cm
- Lub khob = r = 2 cm, t = 4 cm
- Pob = r = 3 cm
- Raj = r = 2 cm, t = 3.5 cm
- Square Pyramid = s = 2 cm, t = 4 cm
Kauj Ruam 3. Xam thaj tsam ntawm txhua qhov duab
Tam sim no, txhua yam koj yuav tsum ua yog ntsaws qhov ntev ntawm txhua tus duab rau hauv cov mis kom pom thaj tsam ntawm txhua qhov duab thiab koj ua tiav. Nov yog li cas:
- Luas alas = 6 x 3.52 Luas = 73,5 cm2
- Qhov chaw ntawm lub khob hliav qab = (2 x 4) + x 22 Luas = 37,7 cm2
- Luas = x x 4 x 32 = 113,09 cm2
- Qhov chaw ntawm lub tog raj kheej = 2π x 22 + 2π (2 x 3, 5) = 69, 1 cm2
- Cov cheeb tsam saum npoo ntawm lub xwmfab puag ncig = 22 + 2 (2 x 4) = 20 cm2
