Answer:
Step-by-step explanation:
l = 12 inches
w = 7 inches
h = 4.5 inches
Surface area = lw + 2wh + 2hl
= 12*7 + 2*7*4.5 + 2*4.5*12
= 84 + 63 + 108
= 255 square inches
If it is a closed box, surface area = 2*(lw +wh + hl)
As it is open, surface area = lw + 2wh + 2hl
Down part of the box : length *width
Upper part of the box = length*width
So, for closed box, 2lw
For open box , lw
