2 sentences for 圆 (yuán — tactful)

1. 他说话做事都很圆。

   tā shuō​huà zuò shì dōu hěn yuán.

   He is very tactful in both his speech and his actions.

   Source: Dong Chinese Dictionary

2. 做人应当外圆内方，讲究原则。

   zuò​rén yīng​dāng wài yuán nèi fāng, jiǎng​jiu yuán​zé.

   One should be flexible on the outside but principled on the inside.

   Source: Dong Chinese Dictionary