Khan Academy: Triangles: Pythagorean Theorem Proof Using Similarity

In this video, Sal introduces the Pythagorean Theorem to viewers, crossing into the realm of geometry. He uses several examples, including right triangles, to illustrate the applications and uses of the Pythagorean Theorem.

This lecture, the second in a series on the Pythagorean Theorem, delves into more complex problems. Primarily, it examines the process of finding the value of a hypotenuse. It is beneficial because the example problem is one in which the...

This lecture, the second in a series on the Pythagorean Theorem, delves into more complex problems. It primarily examines the process of finding the value of a hypotenuse. The example problem is beneficial because the solution is not...

The Pythagorean Theorem works for something other than right triangles; show your class all it can do. Using information from the Pythagorean Theorem, the video shows how to determine whether a triangle is an acute or obtuse triangle....

This video tutorial lesson [4:17] involves solving for the length of one of the legs of a right triangle using the Pythagorean theorem.

This video tutorial lesson [4:32] uses the Pythagorean theorem to find the hypotenuse of a right triangle in an application problem.

This video tutorial lesson [9:52] provides a proof for the Pythagorean Theorem by breaking a right triangle into two similar triangles and setting up ratios of corresponding sides.

Your class knows the Pythagorean Theorem, but can they prove it? A series of three videos shows two proofs of the Pythagorean Theorem and use it to classify triangles. 

Need to find the length of a side of a right triangle? Just use the Pythagorean Theorem! Follow along as the tutor defines the Theorem, explains how it works, then uses it to determine the missing length of a right triangle. 

This video tutorial [13:03] explains that the Pythagorean theorem can only be used on right triangles and explains how it is used. Gives several examples using the Pythagorean theorem to find the unknown side of a right triangle....