3 sentences for 約 (yuē — pact)

1. 双方签署了一项长期贸易条约。

   shuāng​fāng qiān​shǔ le yī xiàng cháng​qī mào​yì tiáo yuē.

   Both sides signed a long-term trade treaty.

   Source: Dong Chinese Dictionary

2. 我们双方已经在合同上正式订了约。

   wǒ​men shuāng​fāng yǐ​jīng zài hé​tong shàng zhèng​shì dìng le yuē.

   Both parties have officially signed the contract.

   Source: Dong Chinese Dictionary

3. 既然答应了别人，就绝不能做负约的事。

   jì​rán dā​ying le bié​ren, jiù jué bù néng zuò fù yuē de shì.

   Since you have given your word, you must never break the agreement.

   Source: Dong Chinese Dictionary