I find the dictionary hints terribly unhelpful in these cases.

The verb is 'dazugehören' (= to belong to it, to go with, to be among), it's conjugated like this:

ich gehöre dazu

du gehörst dazu

er/sie/es gehört dazu

wir gehören dazu

ihr gehört dazu

sie gehören dazu

The dictionary hint however is only for 'gehören' (=to belong) without giving an indication that 'dazu' is a part of the verb. And then it's translated as 'are fitting', 'be fitting', which is not only wrong, but also doesn't help with this sentence - hence the confusion in the comments.

I don't see how this is the translation.

This could be a context: [at IKEA] "Hmm, darling, I love this cabinet, but it looks much nicer with the mirrors. How much are those? Are they sold separately?" - "No, the mirrors just come with it."

I think the original German sentence could also be translated literally, like "No, the mirrors just belong to it."

What is gehoeren doing in this sentence, then?

Just incase a member of the Duo staff comes across this, I'd like to add too that the word "dazu" is incredibly poorly taught and I don't really understand it. I'm memorising it than I am learning how it works.

or "the mirrors just belong with it"...(perhaps?)

i hate this sentence

I tend to understand this sentence as "No the mirrors belong here".

That is unbelievably rare to guess that translation. I hate these, because I've lost a heart because of it :( But, this is how duolingo can evolve :)

Whatever dazu

You guys are doing better than me, i wasn't even close

This one was way too odd.