Range simply means the smallest number subtracted from the biggest number. Initially, the scores were 70, 72 and 68 then making the range 68-72 = 4. Now a new score is added which is 100 and it is obviously the biggest number now. So we subtract 68 from 100 that is ; 100-68= 32. This new range is 8 times more than the former. That is, 32/4 = 8.
So u have to add all the sides up. which will give you 6 + 6√3 + 6 +6√3 because their opposite and parallel lengths and widths are equal that gives you 12 + 12√3 so ans is 12m + 12√3m