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# Why Is Algebra Useful?

Is algebra actually useful to anybody? Might it even be useful in your daily life? Absolutely! Keep on reading to find out how.

By
Jason Marshall, PhD,
May 24, 2013
Episode #154

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In the last episode, we began talking about how to solve equations. We’re certainly not finished with that topic yet—and we’ll come back to it soon enough—but today I want to tackle a different but related question: Is algebra actually useful in the real world? It probably won’t surprise you that my eventual answer is going to be: Absolutely—algebra is super useful! But why exactly? Stay tuned because that’s precisely the question we’ll be answering today..

## The Story of Knot Dude

To get things started, let’s jump into our algebraic time machines and travel back about 4,500 years…back to the time when the Great Pyramid of Giza was being built in Egypt. Imagine if you will—since no, this isn’t a true story—that at that time there was a young guy who loved to tie knots in rope…tons and tons and tons of knots. Not surprisingly, everybody thought this guy—we’ll call him Knot Dude—was kinda strange, but he really didn’t care because he was absolutely fascinated by his knots.

Now, it turns out that Knot Dude’s dad—aka, Papa Knot—was a prominent member of Egyptian society. In fact, Papa Knot was the person in charge of figuring out how to build the foundation for the Great Pyramid. And that was not a job to be taken lightly since this is a big pyramid—about 750 feet long on each side and 450 feet high!

Not having much of a social life, Knot Dude spent a lot of time in the evenings listening to his father complain about the difficulty of his job. In particular, one problem was proving quite vexing: how to line up the four walls of the foundation of the pyramid so they all would meet to form a giant perfect square. After all, without a perfectly square base, the pyramid wouldn’t be a pyramid—it’d just be a mess.

What’s the key to getting the foundation to come out right? Well, Papa Knot knew that if he could come up with a way to make sure that each of the four walls came together and formed perfect corners known as right angles—the kind you see in the corners of a perfect square—then his foundation would also be perfect. But for the life of him, he couldn’t figure out how to do it.

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