square stroke

例句：

1. 1.The table is square and has four legs.
   桌子是方的，有四条腿。
2. 2.The room is square and has a big window.
   房间是方的，有一个大窗户。
3. 3.The square of a number is the number multiplied by itself.
   一个数的平方是该数乘以自身。