Tutoring - E-learning mini-lesson, unscripted by Mike Jack
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EnglishVoice Age
Young Adult (18-35)Accents
North American (General) North American (US West Coast - California, Portland)Transcript
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Hello and welcome to another studies with studios tutoring session I am still boast your tutor from math, English and all things in between. Today we're going to talk about the question. What is pie Now? This is a question that I've been asked many times over the years by many different students. And usually when people ask what is pie, they don't just want to know the numbers. If you look up the numbers for pie, you'll find out that PI is equal to 3.1415 dot, dot dot and I say dot, dot dot Because it does go on forever. It is what is known as an irrational number, right? The decimal is never going to stop, and it's never going to repeat any kind of pattern. So at a certain point we just kind of give up and we're like, Okay, 3.14 that's good enough. So we're going to address the question. Why is pi 3.14 so on and so forth? And if that's the case, if it's such a weird number, how did people find it and learn to use it in the first place? So I want you to think way, way, way back when? Now this is before smartphones. This is even before calculators. People were looking at things in terms of what they could measure, what they could see and what they could add, subtract, multiply and divide it by hand. For some of you, that sounds kind of scary, but think about it from that context. Now how would they find a number like 3.1415 so on and so forth if they can't use a calculator? So here's how in ancient Greece and probably in a bunch of other places when people were looking at shapes like squares, triangles, circles, they started to notice patterns about them. Pi is the number that was found because when people were looking at circles, they discovered that there was a very common pattern to describe the distance across the circle and the distance all the way around the circle. Now, this is something you can actually check out for yourself, and all you really need is a bit of string that you can use to see. OK, this one's about twice as long. This one's about three times longer. This one's about four times as long. So here's we're gonna dio. If you take a piece of string and a paper towel roll, well, that's all you need. You can pull the string across the widest part of the circle, right? And look at how far does it go? It's maybe a few inches, but we don't even need to know exactly how much that is. We just need to see how it compares to the distance around the circle. So if you take that string, put it across that paper towel to rule and then mark off that section of the string, take the rest of the string and wrap it around the paper towel. You'll be able to see the distance around. Now we have two things. We have the distance cross that is called the diameter and the distance around that is called the circumference. If you compare those one side by side, what do you notice? Well, you'll notice that the circumference the distance around is longer than the diameter the distance cross. But how much longer would you say is about two times as long? About three times as long, about four times as long in this case is going to be pretty close to three times as long. If you took that diameter and brought it up against thesis er conference right. If you have this conference all straightened out and you're able to see exactly how long it is, if you took the diameter and laid it out along the circumference, you would see that you could have three diameters and still have a little bit extra that you hadn't quite covered on the circumference. And that has actually the number 3.14 If you were to calculate it out and you found out, let's say the diameter of a circle is exactly one unit long. We might not know how long the unit is, but that's OK. If the diameter of the circle is exactly one unit long in the circumference, the distance around is going to be exactly 3.1415 and so on. Units long. And that's where they got pie. And we still use it that way today. So pie. It is a number, but it's also a ratio. Operation means that it can help us compare two things together. Pi tells us that for however long the diameter is, we need a little bit more than three times that length to go all the way around the circle. That same ratio shows up when we're looking for area. It's used a little bit differently there. The formula for area involves taking half of the diameter, multiplying by itself and then once get multiplying by 3.14 But that's something that you can get into with your teacher or look up online. Really. The point of this particular tutoring session is to understand why pie is 3.14 and how we can use it. Because if we understand what it means and how people found it, it will seem a lot less complicated when it's written on, say, a test form. All right, that's it for today's lesson. Let's do a quick recap of what we've learned. Pi is number 3.14 It is also a ratio and its ratio that tells us about how much of a length who would need to go all the way around a circle if we know the diameter. If we know the diameter in the distance all the way around the circle or the circumference is going to be 3.14 times that. That is your many demo on pie. Please take a look at other studies with Stumbo study sessions. Thank you for listening.