Khan Academy on a Stick
Right triangles
Triangles are not always right (although they are never wrong), but when they are it opens up an exciting world of possibilities. Not only are right triangles cool in their own right (pun intended), they are the basis of very important ideas in analytic geometry (the distance between two points in space) and trigonometry.
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Pythagorean Theorem
ccPythagorean Theorem
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The Pythagorean theorem intro
ccIntroduction to the Pythagorean Theorem
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Pythagorean Theorem 1
ccPythagorean Theorem 1
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Pythagorean Theorem 2
ccPythagorean Theorem 2
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Pythagorean Theorem 3
ccPythagorean Theorem 3
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Introduction to the Pythagorean Theorem
ccRight triangles and the Pythagorean Theorem
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Pythagorean Theorem II
ccMore Pythagorean Theorem examples. Introduction to 45-45-90 triangles.
Pythagorean theorem
Named after the Greek philosopher who lived nearly 2600 years ago, the Pythagorean theorem is as good as math theorems get (Pythagoras also started a religious movement). It's simple. It's beautiful. It's powerful. In this tutorial, we will cover what it is and how it can be used. We have another tutorial that gives you as many proofs of it as you might need. In thi
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Garfield's proof of the Pythagorean Theorem
ccJames Garfield's proof of the Pythagorean Theorem.
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Bhaskara's proof of Pythagorean Theorem
An elegant visual proof of the Pythagorean Theorem developed by the 12th century Indian mathematician Bhaskara.
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Pythagorean Theorem Proof Using Similarity
ccProof of the Pythagorean Theorem using similarity
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Another Pythagorean Theorem Proof
Visually proving the Pythagorean Theorem
Pythagorean theorem proofs
The Pythagorean theorem is one of the most famous ideas in all of mathematics. This tutorial proves it. Then proves it again... and again... and again. More than just satisfying any skepticism of whether the Pythagorean theorem is really true (only one proof would be sufficient for that), it will hopefully open your mind to new and beautiful ways to prove something very powerful.
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30-60-90 Triangle Side Ratios Proof
ccProving the ratios between the sides of a 30-60-90 triangle
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45-45-90 Triangle Side Ratios
ccShowing the ratios of the sides of a 45-45-90 triangle are 1:1:sqrt(2)
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30-60-90 Triangle Example Problem
ccUsing what we know about 30-60-0 triangles to solve what at first seems to be a challenging problem
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Area of a Regular Hexagon
ccUsing what we know about triangles to find the area of a regular hexagon
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45-45-90 Triangles
ccIntroduction to 45-45-90 Triangles
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Intro to 30-60-90 Triangles
ccA few more 45-45-90 examples and an introduction to 30-60-90 triangles.
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30-60-90 Triangles II
ccMore examples using 30-60-90 triangles.
Special right triangles
We hate to pick favorites, but there really are certain right triangles that are more special than others. In this tutorial, we pick them out, show why they're special, and prove it! These include 30-60-90 and 45-45-90 triangles (the numbers refer to the measure of the angles in the triangle).