Answer: 52.8 m
Explanation:
What you want to try to do when you come across these shapes is to think about it as two different shapes instead of one. The bigger rectangle should have a perimeter of 31 (12.3+12.3+3.2+3.2). Now for the bottom rectangle, you have to solve for one of the side lengths. Subtract 3.2 from 8.6 (as 3.2 is already being used by the top rectangle's perimeter) to get 5.4. The perimeter of the smaller rectangle should be 21.8 (5.5+5.5+5.4+5.4). Now add 31+21.8 to get 52.8 and that should be the total perimeter of your shape. :)