To find the answer for that question you have to find the area of rectangle first, so you say 60*80 which equals to 4800 cm squared and then find the area of the box and not its volume so you say: 2(16*10)=2*160=320 cm squared
4(16*27)=4*432=1728 cm squared
add 320+1728= 2048 cm squared
Finally, to find the area of the left poster board you have to subtract the area of the rectangle which is 4800 cm squared by the area of the box which is 2048 cm squared so 4800-2048=2752 cm squared
4(16*27)=4*432=1728 cm squared
add 320+1728= 2048 cm squared
Finally, to find the area of the left poster board you have to subtract the area of the rectangle which is 4800 cm squared by the area of the box which is 2048 cm squared so 4800-2048=2752 cm squared