Ib lub duab plaub tsis tu ncua yog lub ntsej muag 2-dimensional (muaj lub kaum sab xis tsawg dua 180 degrees) nrog ob tog sib luag thiab cov ces kaum sib npaug. Ntau lub duab plaub, xws li cov duab plaub lossis daim duab peb sab, muaj cov qauv yooj yim hauv cheeb tsam. Txawm li cas los xij, yog tias koj tab tom ua haujlwm nrog cov duab uas muaj ntau dua 4 sab, txoj hauv kev zoo tshaj los daws qhov no yog siv cov qauv uas siv qhov apothem thiab ib puag ncig ntawm cov duab. Nrog rau kev siv zog me ntsis, koj tuaj yeem pom thaj tsam ntawm cov duab tsis tu ncua hauv ob peb feeb xwb.
Kauj ruam
Ntu 1 ntawm 2: Xam Xaj
Kauj Ruam 1. Xam ib puag ncig
Ib puag ncig yog qhov ntev ua ke ntawm cov qauv ntawm ib qho duab ob sab. Rau cov duab ntau zaus, ib puag ncig tuaj yeem suav los ntawm kev sib tw qhov ntev ntawm ib sab los ntawm tus lej ntawm ob sab (n).
Kauj Ruam 2. Txiav txim siab qhov apothem
Lub apothem ntawm ib lub duab plaub tsis tu ncua yog qhov deb tshaj plaws ntawm qhov chaw mus rau ib qho ntawm nws ib sab los ntawm kev tsim lub kaum sab xis. Nrhiav qhov apothem yog qhov nyuab nyuab dua li suav thaj tsam.
Cov mis rau xam qhov ntev ntawm qhov apothem yog: qhov ntev ntawm sab (s) faib los ntawm (2 zaug tangent (ziab) (180 degrees faib los ntawm tus naj npawb ntawm ob sab (n)))
Kauj Ruam 3. Paub cov mis raug
Thaj chaw ntawm ib qho duab ntau niaj zaus tuaj yeem pom siv tus qauv: Luas = (a x k)/2, nrog a yog qhov ntev ntawm qhov apothem thiab k yog ib puag ncig ntawm lub polygon.
Kauj Ruam 4. Nkag mus rau qhov tseem ceeb ntawm a thiab k hauv cov mis thiab nrhiav thaj tsam.
Piv txwv li, cia peb siv lub hexagon (6 sab) nrog sab ntev (s) ntawm 10.
- Qhov puag ncig yog 6 x 10 (n x s) sib npaug 60. Yog li, k = 60.
- Lub apothem tau suav los ntawm cov qauv sib cais los ntawm kev nkag mus rau 6 thiab 10 rau qhov muaj txiaj ntsig ntawm n thiab s. Qhov tshwm sim ntawm 2 tons (180/6) yog 1.1547. Tom qab ntawd, 10 faib los ntawm 1.1547 sib npaug 8.66.
- Lub cheeb tsam ntawm lub polygon yog Cheeb Tsam = a x k / 2 lossis 8.66 npaug 60 faib los ntawm 2. Cheeb tsam yog 259.8 chav nyob sib npaug.
- Tsis tas li nco ntsoov tias tsis muaj cov ntawv hauv kab zauv hauv cheeb tsam yog li yog tias koj suav 8.66 faib ua 2 zaug 60, qhov txiaj ntsig yuav zoo ib yam li 60 faib ua 2 zaug 8.66.
Ntu 2 ntawm 2: Nkag Siab Lub Tswv Yim Hauv Txoj Kev Sib Txawv
Kauj Ruam 1. Nkag siab tias cov duab ntau ntau niaj zaus tuaj yeem xav txog kev sau ua ib daim duab peb sab
Txhua sab sawv cev rau ib lub hauv paus ntawm daim duab peb sab thiab tus naj npawb ntawm cov voos peb sab hauv cov duab sib npaug yog sib npaug nrog cov lej. Txhua daim duab peb sab muaj tib lub hauv paus ntev, qhov siab thiab thaj chaw.
Kauj Ruam 2. Nco qab cov mis rau thaj tsam ntawm daim duab peb sab
Thaj tsam ntawm ib daim duab peb sab yog 1/2 npaug ntawm qhov ntev ntawm lub hauv paus (qhov ntev ntawm sab hauv sab hauv ntawm lub duab plaub) lub sijhawm qhov siab (apothem ntawm cov duab ntau zaus).
Kauj Ruam 3. Saib qhov zoo sib xws
Ib zaug ntxiv, cov qauv rau cov duab ntau ntau tsis tu ncua yog 1/2 npaug ntawm apothem lub sijhawm ib puag ncig. Qhov puag ncig tsuas yog qhov ntev ntawm ib sab zauv tus lej ntawm ob sab (n). Rau cov duab ntaug tsis tu ncua, n kuj sawv cev rau tus lej ntawm daim duab peb sab uas ua rau daim duab. Yog li, cov mis tsuas yog thaj tsam ntawm daim duab peb sab lub sijhawm ntawm cov voos peb sab hauv cov duab peb sab.
Lub tswv yim
- Yog xav paub ntau ntxiv txog yuav ua li cas ua cov hauv paus plaub hau, nyeem kab lus Yuav Ua Li Cas Thiaj Li Muab Cov Hauv Paus Square Cov Hauv Paus thiab Yuav Ua Li Cas Thiaj Li Muab Cov Hauv Paus Square.
- Yog tias koj lub octagon (lossis lwm yam duab plaub) tau muab faib ua nws daim duab peb sab thiab koj paub thaj tsam ntawm ib ntawm peb daim duab hauv qhov teeb meem, koj tsis tas yuav paub qhov apothem. Tsuas yog siv thaj tsam ntawm ib daim duab peb sab thiab suav nrog cov lej ntawm ob sab ntawm thawj daim duab peb sab.
