Add up all the numbers then divide how many ever digits there are
898 mm because 8.98 is a lot smaller, it's only in the ones place.
Well to find the value of the interior angle of a hexagon it would be out of a total of 720 degrees therefore just subtract the values of the known interior angle values and you should be able to get the value of the interior angle of X
5 2/3 is the answer to your question