Cov duab ntawm lub tawb muaj puag ncig, square, octagonal, hexagonal thiab lwm yam duab.Vim tias qhov chaw ncig siv thaj chaw loj, nws yog qhov tsim nyog rau kev ua ub no ntawm cov noog, thiab nws tsis yooj yim rau kev raug mob, yog li nws yog nrov rau txhua tus neeg.Lub tawb yog nyiam rau tus txiv neej nyiam noog, vim nws nyob ...
Nyeem ntxiv