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Lesson 6: Pythagorean theorem proofs

Another Pythagorean theorem proof

Visually proving the Pythagorean Theorem. Created by Sal Khan.

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• How con we use this proof and theorem in are daily life's? I don't see how we could use it.
• The real value of teaching proof in geometry class is to teach a valuable life skill. You learn to think logically, step-by-step, to learn to distinguish what you think is true from what can be shown to be true. We call these skills "critical thinking". These skills can keep you from being deceived.

You don't have to try very hard to find an advertisement or other claim that may or may not be true. There is great advantage in having the skills to examine a claim one piece of evidence at a time until you know the claim if false or know that it is well-supported and may be true.

So, geometry is a class where the basics of that skill are taught. Will you need to know in most professions whether two triangles are congruent? No, you won't. Will you need to be able to analyze claims to see if they are rumor, myth, wild speculation, impossible, or well-supported and likely true? Yes, you will. And you use the same kind of skills (different details, of course) to do both.
• Why is line b the height? It seems much smaller than line c. So how is it the height? -
• When Sal flipped the parallelogram so that b_ was the base, I found it helpful to flip the line _b that was on the triangle to the right of the parallelogram as well in my head. Since they are at a right angle to each other, it showed me that the hight of the parallelogram was in fact _b_.
• We shall call this "Sal's proof of the Pythagorean Theorem"
• My brain has rotated as many times as Sal has rotated shapes in this video.
• If you have been able to complete the other workouts on the Pythagorean theorem, then you should be able to figure out what to do from the start, without all the flips. He is just explaining how people discovered the Pythagorean theorem.
• whats this mans iq?
• A Pythagorean IQ.
• Who proved this theorem?
• The Pythagorean Theorem was known long before Pythagoras, but he may well have been the first to prove it.
• At I don't understand how he found out that the height was b. What are the processes involved in finding the height. It just doesn't seem logical either.
• There is a version of side b that was rotated 90 degrees. It is used as the altitude of the parallelogram.
• My mind has been blown 4 times in a row