2 sentences

1. 勾股定理中的“弦”指的就是直角三角形的斜边。

   gōu gǔ dìng​lǐ zhōng de“ xián” zhǐ de jiù shì zhí​jiǎo sān​jiǎo​xíng de xié biān.

   The 'xian' in the Pythagorean theorem refers to the hypotenuse of a right triangle.

   Source: Dong Chinese Dictionary

2. 在中国古代数学中，直角三角形较长的直角边被称作股。

   zài Zhōng​guó gǔ​dài shù​xué zhōng, zhí​jiǎo sān​jiǎo​xíng jiào cháng de zhí​jiǎo biān bèi chēng​zuò gǔ.

   In ancient Chinese mathematics, the longer leg of a right-angled triangle was called the 'gu'.

   Source: Dong Chinese Dictionary