i'm suppose to show how to construct each of the following: a+b,ab,a/b,a-b, a^(1/2) .... a,b >0 This has to do with constructible numbers using the ruler and compass. So i know that a number is constructible if it the distance (or negative distance) between two constructible points, but I suppose I don't really need such a fact. hmm... SO how do i start this? Can I just look at points a, and b as vectors. I'm sure if I get help with a+b, I can start working on the rest. thanks..