Answer:
1164
Step-by-step explanation:
Surface area is the sum of the areas for all the faces. So 20×15= 300 since there is another one like that you multiply that answer by 2. Then 16×12= 192 then repeat and multiply 192 by 2. Then 12×15= 180 and since there is only one you dont multiply it by 2. Now add (192×2) + (300×2) + 192.
384 + 600 + 192 = 1164
