Now those of you taking trigonometry, that particular type of math is very useful for making maps like this because it allows you to measure heights and distances without actually having to go there.
现在你要用三角函数。 这种特别的数学知识 在做一张岩洞地图的时候特别有用。 因为它可以让你在不走过去的情况下 衡量高度和距离。