zài / zhì / tú / kè / shàng / ， / lǎo / shī / ràng / wǒ / men / yòng / gāng / qū / chǐ / huà / chū / jīng / què / de / zhí / jiǎo / 。

在制图课上，老师让我们用钢曲尺画出精确的直角。

In the drafting class, the teacher had us use a steel set square to draw precise right angles.