You can use the Applying Pythagorean Theorem in real life. If you have an object and you want to find the diagonal of it you can use Applying Pythagorean Theorem to figure it out. Say you have an object that is 40 inches by 32 inches, you have to square 40 and 32, so 40*40= 1600 and 32*32= 1024. Then you add 1600+1024= 2624. Then you have to find the square root of 2624 which is 51.2 (I rounded to the nearest tenth). People can use this if they want to know the diagonal of and object.