# Video: The Converse of the Pythagorean Theorem

What can the converse of the Pythagorean theorem be used for?

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### Video Transcript

What can the converse of the Pythagorean theorem be used for?

First of all, what is the Pythagorean theorem? When using the Pythagorean theorem, we must begin with a right triangle. If the triangle does not have a 90-degree angle, then the Pythagorean theorem cannot be used. And if we have side lengths π΄, π΅, and πΆ, then the square of the longest side β the side across from the 90-degree angle β is equal to the sum of the squares of the shorter sides.

So we wanna know about the converse of the Pythagorean theorem. Itβs essentially working in the other direction. Instead of starting with a 90-degree angle in a triangle, the converse will begin with using all three sides of a triangle and then finishing or ending by figuring out if there is indeed a right angle in this triangle.

So what can the converse of the Pythagorean theorem be used for? It can be used for demonstrating that a triangle has a right angle.