## Thursday, February 21, 2008

### How to steal a pen i.e. Geometry!

In our Geometry lecture (last Thursday?) Dr. K mentioned an excellent way to \sout{steal} borrows someone's pen, and that to by using Geometry! Any ideas?

Well maybe the title should read how to steal "another pen". Say you have two pens. Now make a plane out of these i.e. a cross of some sort, or a right angle. Then ask your very keen and interested audience, about where the vector c= a x b would be? I.e. which direction it would be.

Naturally someone would grab their pen and try to show you, and there is your cue to "borrow" a pen. Claim that the student is holding the pen incorrectly; take it and show them the correct direction (i.e. perpendicular to the other two pens) and there you have one more pen than you previously did!

There's your practical application for maths, to those who always moan about maths not applying to real world situations. (Or maybe someone needs to go to sleep....)

It was the cross product which I mentioned above by the way, and I want to write two lines about something to do with it. However, I will either edit this and insert the two lines or post them tomorrow. (To make them lines look neat I will need to use LaTeX and I have not the energy to fiddle around with that!)