square college cap

例句：

1. 1.The table is square and has four legs.
   桌子是正方形的，有四条腿。
2. 2.The square of a number is the amount of area it covers.
   一个数的平方是它覆盖的面积。
3. 3. The square of pi is approximately 98.5457.
   π的平方大约是98.5457。