First of all, it's clear from the Pythagoras' theorem that a is the square root of ^2 + ^2.

首先,根据毕达哥拉斯定理,勾股定理在西方被称为"毕达哥拉斯定理"

耶鲁公开课 - 基础物理课程节选

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

You know, if you're wandering through Harvard Square and you see an out-of-work Harvard grad, they're handing out examples of square roots, they'll give you an example and you can test it to see is the square root of 2, 1.41529 or whatever.

你知道，如果你从哈佛校园里穿过去,你看见了一个失业校友，正在派发平方根的示例，他们会给你一个例子,而你会检查2的平方根是1。41529或者别的什么。

麻省理工公开课 - 计算机科学及编程导论课程节选

"Cheshire police recently did a root-cause analysis of more than 2, 000 incidents in a 12 month period and found they were linked to alcohol, drugs, driving and mental health issues, " she said.

BBC: Police generic

An open G chord is technically third position given its location of the root note, but in Rock Band 3, that particular variant displays a "2" that falls on the A string.

ENGADGET: Rock Band 3 Pro guitar preview: the guitarist vs. the guitar hero