Question

the perimeter of the figure below is 151.3 ft. find the length of the missing side. (note: diagram is not to scale)

Explanation:

Step1: Sum known side lengths

$11.3+(10.5\times8)+(23.2\times2)$
$=11.3 + 84+46.4$
$=141.7$

Step2: Find missing side length

Let the missing side length be $x$. The perimeter is the sum of all side - lengths. So $141.7 + x=151.3$. Then $x = 151.3−141.7$
$x = 9.6$

Answer:

$9.6$ ft