you can look at those dots, for example, you see (2,8) and (2,2) then look at y and the difference is 6. so if you see it like that, (2,8) and (5,8) is 3, (5,8) and (5,4) would be 4, (5,4) and (8,4) would be 3, (8,4) and (8,2) would be 2, and lastly (2,2) and (8,2) is 6
Now you add all of them up which will be 6+3+4+3+2+6 = 24
so the perimeter of this figure is 24