Naked Science Forum

General Science => General Science => Topic started by: pink_person on 17/04/2005 00:05:33

Title: Three Points
Post by: pink_person on 17/04/2005 00:05:33

Okay, i have tried to figure this out, and i know that triangles help
a bridge better support a heavy weight, but what is it exactly that
makes it work? i can't seem to put it into words...or an equation...
will someone please help me?

Pink

Title: Re: Three Points
Post by: daveshorts on 17/04/2005 02:53:09

I am not sure if this is just restating the obvious but hey...

If you have a triangle, you cannot move one of the corners relative to the other two without changing the length of a side, so it has to be rigid.

Looking at other shapes, in order to move one point the only way I can do it is by moving at least 3 others, in a triangle there are only two other points so you can't..

 You could possibly proove this using cunning geometry but it is far too late, and I need to go to bed.