Her design is made up of two long black granite pieces that meet at an angle.

VOA: special.2009.05.06

But because there's this lone pair here, it's pushing down on the other bonds, 5° so we end up with an angle of less than 109 . 5 degrees.

但因为这里有孤对，它会把其它键向下压，所以键角会小于109。

麻省理工公开课 - 化学原理课程节选

If I pick an angle of 60 degrees, these are some numbers like half and root 3 over 2.

要是我选择一个 60°的角,上面的系数就会是二分之一和二分之根号三

耶鲁公开课 - 基础物理课程节选

So if we still have an angle of a 109 . 5 degrees, and again, we still have four unpaired electrons available for bonding, we can make one of those bonds with another s p 3 hybridized carbon, so we're going to make up one pair here.

如果键角仍然是109。,同样，我们还有4个未配对的电子可以用来成键，我们可以用其中的一个,和另外一个sp3杂化碳原子成键，这样我们可以组成一对。

麻省理工公开课 - 化学原理课程节选