"The district is the same."
Translation:Είναι η ίδια περιφέρεια.
I was only given one η to use, so I skipped the second one and got marked wrong. Not sure why the weird word order that is the preferred translation works. Every so often this course uses a different word order without explanation why. (That's why I looked at the discussion, not to complain!)
The preferred Greek word order is what we deem most common as you can see from the heading on this page. The other suggested by "24stakaman" above is an alternative.
It would seem from you description of the exercise that you were given the words to choose from and it's clear that Duo was expecting the principle translation which requires only one "η". In those exercises, only one possible translation can be accepted.
Because Greek is such a highly inflexed language it's often possible for a variety of word orders to be possible. We always attempt to give the most common one and the one that exemplifies the component being taught.