Answer:
13) easy but long way, count all the blue squares
harder way but fast way, multiply length and width of blue box and subtract length*width of white box inside of blue box the answer would be 80
14) basically the harder way but fast way mentioned above
15) the smallest possible perimeter is achieved when you calculate less of the longer side and more of the short side. therefore, lining the pictures with the 4inch side as the length and 5 inch side as the width in a line, it would give you a perimeter of 5+5+4+4+4+4+4+4=34
Explanation:
13: remember, these are coordinates and not the actual number.
these are the measurements of the blue box
length, 16-2 = 14
width, 14-4=10
these are the measurements of the white box inside the blue box
length, 14-4 =10
width, 12-6=6
find area of both which comes to 140 and 60. subtract 60 from 140 to get 80