Answer:
512
Explanation:
To start off with you can take the area of the the whole rectangle with the boxes inclosed to get (32+8) times (8+8) to get
40x16= 640ft
From their, find the areas of the two boxes inclosed in the rectangle
b1= 8x8= 64ft
b2= 8x8= 64ft
then you can subtract the two boxes areas from the larger rectangles area to get your answer of
640-64-64= 512ft