Hi guys I'm reading a book about linear programming and network flows. In chapter 2 when it talks about convex sets and their analysis it talks about extreme points and extreme directions of a convex set. I understand the definitions of extreme points and extreme directions, but I don't know how I should find them. Unfortunately the book doesn't show how to find them with examples. :( I also don't know what a 'slack variable' is. I guess it must've been defined somewhere but I missed it :/ Any helps would be appreciated.