3 sentences

1. 他已经定好了下周回北京的机票。

   tā yǐ​jīng dìng​hǎo le xià zhōu huí Běi​jīng de jī​piào.

   He has already booked a flight back to Beijing for next week.

   Source: Dong Chinese Dictionary

2. 计划已经定好了，就别再来回折腾了。

   jì​huà yǐ​jīng dìng​hǎo le, jiù bié zài lái​huí zhē​teng le.

   The plan is set; stop making unnecessary changes to it.

   Source: Dong Chinese Dictionary

3. 这次面试对他来说只是例行公事，因为职位已经定好了。

   zhè cì miàn​shì duì tā lái shuō zhǐ shì lì​xíng gōng​shì, yīn​wèi zhí​wèi yǐ​jīng dìng​hǎo le.

   This interview was just a formality for him, as the position had already been decided.

   Source: Dong Chinese Dictionary