zài / jǐ / hé / kè / shàng / lǎo / shī / jiǎng / jiě / le / qiē / xiàn / yǔ / bàn / jìng / zhī / jiān / de / guān / xì

在几何课上，老师讲解了切线与半径之间的关系。

In geometry class, the teacher explained the relationship between a tangent line and a radius.