Greetings, Secret Agent Math! Your mission, should you choose to accept it, is to figure out where you are on Earth relative to the equator. Why might you need to be able to figure this out? Who knows! But a secret agent like yourself is always curious to learn new things, right? After all, you never know when one of these skills is going to come in handy.

Perhaps it’ll be when you’re on that super secret mathematically-oriented spy mission to crack the code used to encrypt that really important message. Or perhaps it’ll be when you’re deploying your particularly well-honed set of mathematical skills to solve that riddle that’s going to help you save those people from that thing. Or … whatever.

The point is, you never know when figuring out where you are on Earth relative to the equator—by which I mean figuring out your latitude—is going to come in handy. So, as every good secret agent skilled in the fine and beautiful art of mathematics has done before, today we’re going to add this trick to our repertoire. Stay tuned to find out how it works!

Recap: What Is Latitude?

Before we rejoin Secret Agent Math and the quest to pinpoint your latitude on Earth, we’d first better recap what we mean by latitude. Those of you who have stared at a globe long enough to notice the grid of horizontal and vertical lines already know pretty much everything you need to understand latitude (as well as its close cousin longitude).