So it's trigonal because we have these three atoms that are bound to the central atom here, and if you picture it, it's actually shaped like a pyramid.

这里三角形是因为,我们有3个原子核中心原子成键，如果你画它，它就是金字塔形的。

麻省理工公开课 - 化学原理课程节选

One, two, three, four, so on each level of the picture I'm drawing, I've seem only to be looking at each number once.

，2，3，4，可见，在我画的,这幅图的每一层上，对每个数字,都只会用到一次。

哈佛公开课 - 计算机科学课程节选

My niece drew a picture of my family once when she was three.

我侄女三岁时画了张全家福

耶鲁公开课 - 死亡课程节选

So if you picture this as our s p 2 carbon atom where we have three hybrid orbitals, and then one p y orbital coming right out at us.

如果你把这想象成sp2碳原子,这里有3个杂化轨道，然后一个py轨道朝向我们。

麻省理工公开课 - 化学原理课程节选