159118

For this question I started off by finding the average of all the numbers which was 4.I then multiplied this by 3 to find an average side(12).After this, I used trial and error to find the answer.(I also made a paper model to make it easier.) The answer was 5 on the top left, 3 on the middle left, 4 on the bottom left, 6 on the bottom middle, 2 on the bottom right, 4 on the middle right, 6 on the top right and 1 on the top middle.