This is the temporary brief explanation I drew on my phone:
The angle here can be found simply with some subtraction and addition of some polygon angles.
This is the actual relation between ##dh## and ##Rd\theta##.
Thank you all brilliant and kind minds so so much for your inputs. I have...
At first, I couldn't understand, but what you said clicked later on.
I followed this and revisited the relationship between ##dh## and ##d\theta##. But I still was unsure what I had to change.
Although this isn't exactly what I looked for, but it hinted me that I may have ignored that:
1) as...
I know I must have done something wrong somewhere here, but I cannot figure out exactly which one
Answer is supposed to be (2/5)MR2
Whatever disaster I have in the last image does not evaluate closely to that at all.
I'm not looking for another way to find the MOI of solid sphere, I would...