1 sentence for 椭圆 (tuǒ​yuán — ellipse)

1. 轨道是一个椭圆，但为了使数学更简单，让我们说它是一个圆圈。

   guǐ​dào shì yī​ge tuǒ​yuán, dàn wèi​le shǐ shù​xué gèng jiǎn​dān, ràng wǒ​men shuō tā shì yī​ge yuán​quān.

   The orbit is an ellipse, but to make the math simpler, let's say it's a circle.

   Source: CCMatrix