u/AxiumTea

(First whole image is from the model answer, 2nd and 3rd are edited by me)

I had been stuck with this question, wondering how the model answer (First image) did it, everything else worked but when I got to question c, I know about the scale factor questions but this specific one it just didn't make any sense. Like "Why did we get the scale factor from DC and AB?" and then the biggest of them all, how come we could hey the CX from BX, I mean it's literally on the same side, wouldn't it make more sense if we got CX from DX? That's it's symmetrical counterpart isn't it? So why not DX? then I just had the thought "Hey, what if I make the other pair of triangle?" (3rd image) and I tried that it made a lot more sense.

My questions are:

Was this always a rule? can we just form another pair of symmetrical triangles when one already exists?

Was my method correct or was I wrong? And if it right, does it follow all the rules of symmetry? are ADX = CBX just as much of symmetrical triangles as ABX = DCX?

First diagram (6 v circuit) -

We want the PD of resistor R, what do we do? We are given the voltage supply by the battery (6 v) Now we first find the DP of the parallel section, which is 2.4v, then we subtracted that 2.4v from the total supply of 6v, getting us 6-2.4 = 3.6 v. That's how we found it, the parallel section played a part in it, which makes sense, that's one's in the same circuit so the voltage was split between the two.

Second Diagram (12 v circuit) - But when trying to find the 2 ohm resistance in this one, we only counted the 4 ohm resistor in series to it, we completely disregarded the parallel section of up there as if it doesn't even exist, why? I thought the voltage split between all the components, why didn't it split this time?