1. Qhov zoo ntawm qhov chaw. Cov qauv tseem ceeb teev cov qhov zoo ntawm qhov chaw ntawm cov hlau rebar, uas yuav tsum tau txiav qhov kawg kom ncaj, qhov chaw yuav tsum tsis txhob muaj kab nrib pleb, qhov txhab thiab qhov quav, thiab yuav tsum tsis txhob muaj qhov tsis zoo thaum siv.
2. Tus nqi tso cai ntawm qhov sib txawv ntawm qhov loj. Qhov degree khoov ntawm cov hlau rebar thiab cov duab geometric ntawm cov hlau rebar tau teev tseg hauv cov qauv cuam tshuam.
3. Yuav tsum tsis txhob muaj cov kab nrib pleb, cov qhov txhab thiab cov quav rau ntawm qhov chaw ntawm cov hlau tuav.
4. Cov pob me me raug tso cai rau ntawm qhov chaw ntawm cov hlau, tab sis lawv yuav tsum tsis pub tshaj qhov siab ntawm cov tav tav. Qhov tob thiab qhov siab ntawm lwm yam tsis zoo ntawm qhov chaw ntawm cov hlau yuav tsum tsis pub ntau dua qhov kev hloov pauv ntawm qhov loj ntawm lawv cov khoom.