1. The problem statement, all variables and given/known data Me again. I again got confused with 2 similar things done differently on two different places. Let's say we have some arbitrary circuit and we want to replace a part of it with thevenin's generator. We also need to calculate effective Thevenin's resistance, which is where i found the problem. Suppose we need to find the effective resistance between points 1 and 2 at the picture. First of all , what does "effective resistance between two points" even mean. Second, I would say "Rt = R2+R3+R4" and according to my workbook that is correct. But if we take a look at this example (at 3:50 for example), we will see that the "hanging" edge is also taken into account. Why ? 2. Relevant equations Thevenin's theorem 3. The attempt at a solution Like i mentioned, I simply used "Rt = R2+R3+R4" which turns out to be correct. Why does the guy in the video take that other edge into account??