Zoo li lub xwmfab zoo thiab paub zoo. Nws yog symmetrical txog nws qhov chaw thiab axes kos raws kab diagonals thiab los ntawm qhov chaw ntawm ob sab. Thiab mus nrhiav thaj tsam ntawm ib lub square lossis nws qhov ntim tsis yog qhov nyuaj. Tshwj xeeb yog qhov ntev ntawm nws sab paub.
Ib ob peb lo lus hais txog daim duab thiab nws cov khoom
Thawj ob lub khoom muaj feem cuam tshuam nrog lub ntsiab lus. Txhua sab ntawm daim duab yog sib npaug rau ib leeg. Tom qab tag nrho, ib tug square yog ib tug tsis tu ncua quadrilateral. Ntxiv mus, nws yuav tsum muaj tag nrho cov sab sib npaug thiab cov ces kaum muaj tib tus nqi, uas yog, 90 degrees. Nov yog qhov khoom thib ob.
Qhov thib peb yog hais txog qhov ntev ntawm kab pheeb ces kaum. Lawv kuj tig tawm kom sib npaug. Ntxiv mus, lawv sib tshuam ntawm txoj cai kaum thiab ntawm qhov nruab nrab.
qauv siv tsuas yog sab ntev
Ua ntej, hais txog cov cim. Rau qhov ntev ntawm sab, nws yog kev cai xaiv tsab ntawv "a". Ces lub square cheeb tsam yog xam los ntawm cov mis: S=a2.
Nws yooj yim tau los ntawm ib tus paub txog lub duab plaub. Nyob rau hauv nws, qhov ntev thiab dav yog multiplied. Rau ib lub square, ob lub ntsiab lus no sib npaug. Yog li ntawd, nyob rau hauv tus qauvtus square ntawm tus nqi no tshwm.
Formula uas qhov ntev ntawm kab pheeb ces kaum tshwm
Nws yog qhov hypotenuse hauv daim duab peb sab uas nws ob txhais ceg yog ob sab ntawm daim duab. Yog li ntawd, koj tuaj yeem siv cov qauv ntawm Pythagorean theorem thiab muab qhov sib npaug ntawm sab uas qhia los ntawm kab pheeb ces kaum.
Tom qab cov kev hloov pauv yooj yim no, peb tau txais tias cheeb tsam square los ntawm kab pheeb ces kaum yog xam los ntawm cov qauv hauv qab no:
S=d2 / 2. Ntawm no tsab ntawv d qhia txog kab pheeb ces kaum ntawm lub square.
Perimeter Formula
Nyob rau hauv cov xwm txheej zoo li no, nws yog ib qho tsim nyog yuav tsum tau nthuav tawm sab ntawm ib puag ncig thiab hloov nws mus rau hauv cov qauv hauv cheeb tsam. Txij li daim duab muaj plaub sab zoo ib yam, lub perimeter yuav tsum tau muab faib los ntawm 4. Qhov no yuav yog tus nqi ntawm sab, uas tuaj yeem hloov pauv mus rau thawj zaug thiab suav thaj tsam ntawm lub square.
Tus qauv dav dav zoo li no: S=(Р/4)2.
Teeb meem rau kev xam
1. Muaj ib tug square. Qhov sum ntawm nws ob sab yog 12 cm. xam qhov chaw ntawm lub square thiab nws perimeter.
Kev txiav txim siab. Txij li cov lej ntawm ob sab tau muab, peb yuav tsum nrhiav qhov ntev ntawm ib qho. Txij li thaum lawv yog tib yam, tus lej paub tsuas yog yuav tsum tau muab faib los ntawm ob. Ntawd yog, sab ntawm daim duab no yog 6 cm.
Tom qab ntawd nws thaj tsam thiab thaj chaw tau yooj yim suav nrog siv cov qauv saum toj no. Qhov thib ib yog 24cm thiab qhov thib ob yog 36cm 2.
teb. Qhov ib puag ncig ntawm ib square yog 24 cm thiab nws cheeb tsam yog 36 cm 2.
2. Nrhiav thaj tsam ntawm ib lub square nrog ib puag ncig ntawm 32 mm.
Kev txiav txim siab. Nws yog txaus tsuas yog hloov tus nqi ntawm ib puag ncig hauv cov qauv sau saum toj no. Txawm hais tias koj tuaj yeem pom thawj sab ntawm lub square, thiab tsuas yog tom qab ntawd nws thaj chaw.
Nyob rau hauv ob qho tib si, qhov kev nqis tes ua yuav ua ntej suav nrog kev faib, thiab tom qab ntawd exponentiation. Kev suav yooj yim ua rau qhov tseeb tias thaj tsam ntawm lub square sawv cev yog 64 mm2.
teb. Qhov chaw xav tau yog 64 mm2.
3. Sab ntawm lub square yog 4 dm. Rectangle qhov ntau thiab tsawg: 2 thiab 6 dm. Qhov twg ntawm ob daim duab muaj thaj tsam loj dua? Ntau npaum li cas?
Kev txiav txim siab. Cia sab ntawm lub square cim nrog tsab ntawv a 1, ces qhov ntev thiab qhov dav ntawm daim duab plaub yog a2 thiab 2 . Txhawm rau txiav txim siab thaj tsam ntawm ib lub xwmfab, tus nqi ntawm a1 yog yuav tsum tau squared, thiab tus nqi ntawm ib daim duab plaub yuav tsum muab faib ua a 2thiab 2 . Nws yooj yim.
Zoo tias thaj tsam ntawm ib lub xwmfab yog 16 dm2, thiab ib daim duab plaub yog 12 dm2. Obviously, thawj daim duab yog loj dua qhov thib ob. Qhov no yog txawm lub fact tias lawv sib npaug, uas yog, lawv muaj tib lub perimeter. Txhawm rau txheeb xyuas, koj tuaj yeem suav cov cheeb tsam. Ntawm lub square, sab yuav tsum tau muab faib ua 4, koj tau 16 dm. Ntxiv ob sab ntawm lub duab plaub thiab muab 2. Nws yuav yog tib tus lej.
Hauv qhov teeb meem, koj kuj yuav tsum teb tias thaj chaw txawv npaum li cas. Ua li no, rho tus lej me los ntawm tus lej loj. Qhov txawv yog 4 dm2.
teb. Cov cheeb tsam yog 16 dm2 thiab 12 dm2. Lub square muaj 4 dm ntxiv2.
pov thawj teeb meem
Zoo. Ib lub xwmfab yog ua rau ntawm ceg ntawm ib qho isosceles txoj cai daim duab peb sab. Ib qhov chaw siab yog ua rau nws cov hypotenuse, uas lwm lub square yog ua. Ua pov thawj tias thaj tsam ntawm thawj yog ob npaug ntawm qhov thib ob.
Kev txiav txim siab. Cia peb qhia cov cim. Cia tus ceg yuav sib npaug rau a, thiab qhov siab kos rau lub hypotenuse yog x. Thaj chaw ntawm thawj square yog S1, lub square thib ob yog S2.
Thaj tsam ntawm lub square ua rau ntawm txhais ceg yog yooj yim los xam. Nws hloov tawm yuav muab sib npaug rau a2. Nrog tus nqi thib ob, yam tsis yooj yim li.
Ua ntej koj yuav tsum paub qhov ntev ntawm lub hypotenuse. Rau qhov no, cov qauv ntawm Pythagorean theorem yog qhov tseem ceeb. Kev hloov pauv yooj yim ua rau cov lus qhia no: a√2.
Vim qhov siab hauv daim duab peb sab isosceles kos rau hauv paus kuj yog qhov nruab nrab thiab qhov siab, nws faib cov duab peb sab loj rau hauv ob qhov sib npaug isosceles txoj cai peb tog. Yog li ntawd, qhov siab yog ib nrab ntawm hypotenuse. Qhov ntawd yog, x \u003d (a √ 2) / 2. Los ntawm no nws yooj yim mus nrhiav thaj chaw S2. Nws hloov tawm yuav muab sib npaug rau a2/2.
Pom tseeb, cov nqi sau tseg txawv raws nraim los ntawm ib qho ntawm ob. Thiab qhov thib ob yog tsawg dua. Raws li yuav tsum tau ua pov thawj.
Ua tsis taus pa - tangram
Nws yog tsim los ntawm square. Nws yuav tsum raug txiav mus rau hauv ntau yam duab raws li qee txoj cai. Tag nrho cov khoom yuav tsum yog 7.
Cov cai xav tias thaum lub sijhawm ua si txhua qhov tshwm sim yuav raug siv. Ntawm cov no, koj yuav tsum ua lwm cov duab geometric. Piv txwv li,duab plaub, trapezoid lossis parallelogram.
Tab sis nws tseem nthuav dua thaum cov silhouettes ntawm cov tsiaj lossis cov khoom tau txais los ntawm cov khoom. Ntxiv mus, nws hloov tawm hais tias thaj tsam ntawm tag nrho cov derivative daim duab yog sib npaug zos rau qhov pib square.
