When I attended the twelth grade in high school (german Gymnasium) I gave the following speech about calculating the length of any vector in space. Now you can download two german versions of the speech as PDF files:
Although we're talking about a teaching speech I can't guarantee its completenes and correctnes. Feel free to use it for your own lessons but don't forget to mention my name and this website as source when using it for another speech.
You want to know more about vectors? (You know, they are not so unnecessary when it comes to programing graphics or even games. ) I'd be glad to write down what I know but only if there's some need for it.
) I'd be glad to write down what I know but only if there's some need for it.