Answer:
7.3 ft.
Explanation:
The perimeter of a geometrical figure is calculated by adding all side lengths up:
The perimeter of the figure in question is 84.6 ft.
2*(3.4) + 2*(11.3) + 6*(6.8) + (7.1) + ? = 84.6 (it's easier if we write equal terms in multiplying form)
77,3 + ? = 84.6 subtract 77.3 from both sides
? = 7.3 is the length of the missing side