polygonal ring structure

例句：

1. 1. The building is designed witha polygonal roof.
   这座建筑的屋顶是多角形的。
2. 2. The carpenter used a polygonal pieceof wood to build the table.
   木匠用一块多角形的木板来建造桌子。
3. 3. The polygonal shape of theroof allows for better ventilation.
   多角形的屋顶设计有利于更好的通风。