ok... so you can find the area of all three rectangles. the smallest would be 11(8)=88 .
And the middle sized one would be 11(15)=165
And the largest rectangle would be 11(17)=187
So, now you know the area of all the rectangles, but you have two triangles left to find their area... you could be thinking that you cant because they are not labeled. But they don't have to be... see, picture this map of the shape all put back together back to a 3d shape.
Then you can see that the width of each triangle is half of the width of the triangles (so half of 11).
Now you can also see that the height of both triangles are the same height as the middle rectangle (so 15).
So to find the area of a triangle, you would do 1/2b(h). so it would be 1/2(5.5)(15) this all becomes 41 1/4
But you have two triangles, and they are obviously the same measurement so what we would do is multiply the area of the one triangle 41 1/4 by 2 .
So now we have 82 1/2 .
Now all you have to do is add all of your areas of the surfaces and this would be 88+165+187+41 1/4 to get the final answer of 481 1/2 or 481.5
I hope you understand, and I hope I helped! ;)