"Why is the shape of your cake like that?"
Translation:Mengapa kuemu bentuknya seperti itu?
So bentuknya can mean "shaped" as in "Why is your cake shaped like that?.
Yes, same same but different.
Same meaning, different grammar (noun versus verb).
It's about the base word and the affixes.
base word = 'bentuk' (noun) = shape, form
'bentuknya' = the/his/her/its shape. (noun)
'berbentuk' = to be shaped. (verb)
1-ID) Mengapa kuemu bentuknya seperti itu?
1-EN) Why is the shape of your cake like that?
2-ID) Mengapa kuemu berbentuk seperti itu?
2-EN) Why is your cake shaped like that?
The first sentence uses: [base word] + [-nya] suffix ==> [noun].
The second sentence uses: [base word] + [ber-] prefix ==> [intransitive verb].