What's the diagonal length of a tv that is 20in tall and 36in width

So I have this formula which is a^2+b^2=c^2
20^2+36^2=c^2
C=41.2 inches. As a result, the diagonal length is about 41.2 inches. Hope it help!

Pythagorean theorem should be used in this case.

a² + b² = c²   where a and b are the sides of the triangle and c is the hypotenuse

This theorem is typically taught as a way to calculate the hypotenuse of a triangle (which is what you are referring to)

But it may mean much more to you if you realize that this is an equation to describe shortest distance from the origin to some coordinate. I have found myself using it more as a way to find distance than I do to measure a length of a physical shape. 

“exterior angles of triangles. an exterior (or external) angle is the angle between one side of a triangle and the extension of an adjacent side. try this drag the orange dots on any vertex to reshape the triangle.” look to get to the answer i explained what it means and other things i hope it you .