And you can set a square where you want it to detect the motion.

你可以设置一个想要录制慢动作的矩形区域。

There's no set square milage, no required population, nothing.

没有设定的平方英里数，没有所需的人口，什么都没有。

One set square was placed in front of everybody.

每人面前都放了一块三角板。

His blue porkpie hat was set very square on his head and chalk-white hair showed under it.

他的蓝色圆帽帽子正方形地戴在头上， 帽檐下露出粉笔白的头发。

Then I learned how to use the tools of masonry: hammers, chisels, the compass, and the set square.

然后我学会了如何使用石工工具：锤子、凿子、圆规和三角板。

The set square helps me make sure the walls I build are straight and true, so that my corners form ninety-degree angles.

三角板帮助我确保我建造的墙是直的和真实的，这样我的角就会形成九十度角。