Question

What am I supposed to do

Answer 1

Im pretty sure you do 14 x 9 which is 126 then do 126 x 3 which is 378mm is your answer          expression: (14mmx9mm)x3mm    answer: 378mm
hope this helps

Answer 2

First focus on the main sides. To find the surface area of one side, you must do LxW (length x width). Which is 9x14. And since there are 2 of these size rectangles, 9x14x12=252 (For the ones on the front and back). Now for the top and bottom, use LxW again, 3x14, and since there are 2 of these size rectangles, 3x14x2=84. Now for the Left and Right sides, 3x9. Once again, there are two of these sizes so 3x9x2=54. Then add all those up, the ANSWER IS 252+84+54= 390