2 sentences for 顶点 (dǐng​diǎn)

1. 正方形的每个顶点都是直角。

   zhèng​fāng​xíng de měi gè dǐng​diǎn dōu shì zhí​jiǎo.

   Each vertex of a square is a right angle.

   Source: Dong Chinese Dictionary

2. 经过长时间的攀登，他们终于到达了山脉的顶点。

   jīng​guò cháng shí​jiān de pān​dēng, tā​men zhōng​yú dào​dá le shān​mài de dǐng​diǎn.

   After a long climb, they finally reached the peak of the mountain range.

   Source: Dong Chinese Dictionary