2 sentences

1. 她现在八十一岁了。

   tā xiàn​zài bā​shí​yī suì le.

   She is now eighty-one years old.

   Source: Tatoeba

2. 根号八十一的计算结果等于九。

   gēn​hào bā​shí​yī de jì​suàn jié​guǒ děng​yú jiǔ.

   The square root of eighty-one is nine.

   Source: Dong Chinese Dictionary