i still dont get it

Ooops     sorry   misread the question....

Look at the front face....   it has   2  x  6 squares = 12 squares   .....the BACK face (the one you can't see) has the same

    so far     2  x 12 square

Now look at the side face.  It has   2 x 4 squares = 8 squares    .... the LEFT face (you can't see) does too...

   add         2 x 8 squares

Now look at the TOP face.  It  has  6 x4 squares     so does the BOTTOM face (you can't see)

add      2 *   6 x 4 

Add up the Reds.....what do you get????

rectangular solid area =2[LW + LH + WH]

=2[6*4 + 6*2 + 4*2]

=2[24 + 12 + 8 ]

=2 x [ 44 ]

= 88  Square Units.

Obviously, two others have already posted their own solution, but I put in a solution earlier at https://web2.0calc.com/questions/helppppp_16#r1

Given that the forum title of this question is "i still dont get it," I assume that you were confused with my solution. You are always strongly encouraged to request for clarification. It is detrimental to you to pretend as if you understand. 

Is there a particular section that confused you? 

Do you understand what "surface area" means?

Is there a particular section where you would like more detail?