Calculating surface normals

[BigMoosie]

Given 3 points in 3D space as cartesian coordiantes (a triangle) I need to calculate the normal for a 3D graphing program I am making. I haven't done any calculus that might help with this and I don't know about linear algebra so Wolfram's solution is of no help:

 

For a polygon (such as a triangle), a surface normal can be calculated as the vector cross product of two edges of the polygon.

 

Can anybody please translate this into an algebraic solution for me? Thankyou.

[shmoe]

Cross product:

 

http://planetmath.org/encyclopedia/CrossProduct.html

 

If your triangle has vertices given by the vectors u,v,and w, then take a=v-u and b=w-u (not the only choices), these will be vectors in the directions of two of the sides. axb and bxa will both give normals, but in opposite directions, axb=-(bxa)