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Lesson 9-4 - Geometry's Most Elegant Theorem

Today, we covered the most famous of geometric theorems:

The Pythagorean Theorem

With the Altitude-on-Hypotenuse Theorem, the proof is pretty straight forward:

One proof of the Pythagorean Theorem

The converse is also true, and is useful in terms of classifying triangles:

Converse of the Pythagorean Theorem

Here's an example of how we might use this theorem:

Example using the Pythagorean Theorem to classify a triangle

Another example follows:

Another example using the Pythagorean Theorem

Other Links
Class Notes
Lesson 9-1
Lesson 9-2
Lesson 9-3
Lesson 9-4
Quiz Topics
Lesson 9-5
Lesson 9-6
Lesson 9-7
Lesson 9-8
Lesson 9-9
Lesson 9-10
Test Topics
Trig Table
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