2 sentences for 正巧 (zhèng​qiǎo)

1. 我去书店时，正巧碰到了我的老师。

   wǒ qù shū​diàn shí, zhèng​qiǎo pèng​dào le wǒ de lǎo​shī.

   When I went to the bookstore, I happened to run into my teacher.

   Source: Dong Chinese Dictionary

2. 我刚准备去车站你就打来电话，时间真是凑得正巧。

   wǒ gāng zhǔn​bèi qù chē​zhàn nǐ jiù dǎ​lái diàn​huà, shí​jiān zhēn shì còu de zhèng​qiǎo.

   I was just about to head to the station when you called; the timing was perfect.

   Source: Dong Chinese Dictionary