# Why can the Pythagorean Theorem only be used with Right Triangles?

##### 1 Answer

Apr 25, 2018

It's not really true. The Pythagorean Theorem (its converse, really) can be used on any triangle to tell us whether or not it is a right triangle.

#### Explanation:

For example, let's check the triangle with sides 2,3,4:

But of course

The Pythagorean Theorem is a special case of the Law Of Cosines for