They want to get as far away from each other possible, the ideal angle is 120. But what we have here is a four-membered ring, so what angle does 90° that have to be, that bond? 90 degrees.

它们想要尽量远离彼此，最理想的是形成120°键角,但现在是个四元环,所以这键角应该多大？

麻省理工公开课 - 化学原理课程节选

If it's in polar form I passed in a radius and angle and I'll compute what the x- and y- value is.

以及半径和角度,但是现在是这样的,不管我是以哪种形式。

麻省理工公开课 - 计算机科学及编程导论课程节选

Now take these two fingers-- the middle finger and the thumb-- and as much as possible, from that 90 degree angle, create a circle.

再让这两个手指-,中指和姆指-,尽可能保持直角时围成一个圆圈。

哈佛公开课 - 幸福课课程节选

So we can have our two hydrogen atoms come in here, and what we will find is - now that we have all of our orbitals filled up -- so thinking about what this angle is here, would you expect it to be less than or greater than what we saw for ammonia before?

我们在这里有两个氢原子，我们会发现,现在我们所有的轨道都填满了-,考虑一下这里的角度，你们觉得它比在氨中看到的,要大还是要小？

麻省理工公开课 - 化学原理课程节选

So I guess I should go back, and let me do this correctly this way. Again, I can look at test, test and I guess test now if I want to get the element out-- angle bracket or square bracket?

但是这不是我想要的对不对？,我认为我该回到这里，让我改正这个错误，好，那么我还是对元组,那么现在我想从test中取出元素来？

麻省理工公开课 - 计算机科学及编程导论课程节选