Answer: 76 meters
Explanation:
top side left blank = 18 because it is congruent to the bottom
left side blank is 4 + 4 + 4 (right side lengths added)
left side blank is 12
add all side lengths together for perimeter
12 + 18 + 4 + 8 + 4 + 8 + 4 + 18 = 76
76 meters