Put the numbers in order from least to greatest, 1.5 × 104, 2.6 × 10-2, 3.5 × 102, 6.2 × 10-1

20.8 (2.6 x 10-2) , 55.8 (6.2 x 10-1) , 156 (1.5 x 104) , 357 (3.5 x 102)

to find the perimeter, you add up all the lengths of the sides. in this case you would have to add up 18+22+40+80 which equals 160.