The perimeter is 86 m.
When you add the 18 with the 11, you get the length of the bottom side, which is 29. When you add the nine and the 6, you get the length of the left side, which is 15. Now add everything together.
18 + 6 + 11 + 9 + 29 + 15 = 86 m
Hope I helped. Good luck!! : )