It's not something you're going to go back and remember it's an opposite side, it's an adjacent side.

不应该再去翻以前的课本,还去回忆哪个是对边,哪个是邻边

耶鲁公开课 - 基础物理课程节选

Which element is shown here? Yeah, nitrogen.

这显示的是哪个元素？对，是氮。

麻省理工公开课 - 化学原理课程节选