TOPIC: Triple Constraints (iron triangle)

I found a study guide online and I see that this is on there for things to study. Is this still a thing that PMI will test on? I haven't run into any questions in the simulator, but that doesn't always mean it is out of scope. The concept is pretty simple. I just want to know if i should waste the brain cells.

If so, where would I find it in the PMBOK?

Thanks,

This concept has been replaced with 'competing project constraints', 'project constraints' or simply 'constraints'.

The triple constraints was a simplified approach. However, starting with PMBOK Guide Fifth Edition PMI realized that it's not just 3 constraints, but there can in fact be many constraints: Scope, schedule, cost, quality, resources and risk (and more!) all compete for our attention, our money, our time, our everything. So forget the "triple" constraints and welcome "project constraints" that all pull for your attention.

OK good to know. Thanks Cornelius.