Feem ntau, cov neeg siv khoom tuaj yeem xaiv lub rooj tsavxwm uas lawv nyiam raws li qhov loj ntawm lawv chav, lossis raws li tus tsim qauv cov lus qhia. Muaj ob txoj kev qhia rau sab saum toj: qhov ntev thiab vertically paving txoj kev, tab sis tsis muaj qhov zoo li no rau square boards. Qhov yuav tsum tau muaj yog qhov lengthwise los yog vertically dimension muab faib los ntawm qhov dav ntawm txhua lub rooj tsavxwm. Txhua square meter ntawm sawb board yog nruab nrog ib tug tshwj xeeb keel ntawm 1.2 meters, thiab txhua square meter square board yog nruab nrog ib tug tshwj xeeb keel ntawm 3.3 meters, thiab 4 dai qhov chaw. Qhov chaw ntawm txhua lub rooj tsavxwm yog thaj tsam ntawm txhua lub rooj tsavxwm muab qhov ntev rau txhua 100mm board. Piv txwv li: U1{{22}0*3{{30}}}00, nws cheeb tsam yog 0.1*{10}}.3M2. U125 * 3000, nws cheeb tsam yog 0.125 * 3=0.375M2. 300 * 300, nws cheeb tsam yog 0.3 * 0.{25}}.09M2. 350 * 350, nws lub rooj tsavxwm cheeb tsam yog 0.35 * 0.35=0.1225M2.
Xa kev nug