zài / shùxué / kèshàng / wǒmen / yòng / Xīlà / zìmǔ / pài / biǎoshì / yuánzhōulǜ在数学课上,我们用希腊字母π表示圆周率。In math class, we use the Greek letter pi to represent the ratio of a circle's circumference to its diameter.