Answer:
22969.39 yd^2
Step-by-step explanation:
Alright to start, lets do the easier part of it, the sides of it. Since it is an octagonal prism, there are 8 rectangular sides to it. Each of these sides can be found with L*W, so use the given length of 15 and width of 6 to do this.
15 * 6 = 90
Since there's 8 of these:
90 * 8 = 720
Now, with the tricky part with the bases of the octagonal prism. Let's find the perimeter of the octagon, so use the top width of each of the rectangles.
6 * 8 = 48 = Perimeter
Now, here's the magic equation to avoid making this more complicated:
2(1+√2)p^2
Then plug in p
2(1+√2)48^2
(2+2√2) * 2304
(2+2.8284)*2304
4.8284*2304
11124.69...
But there's two bases so: 22249.39
Lastly, add this to the 720 from the rectangular prisms.
22249.39+720 = 22969.39
Hope that helps.