What you have to do is find the sume of all of the areas of the rectangles in this rectangular prism.
Lets find the front and back first.
9in * 14in = 126 in^2
9in * 14in = 126 in^2
= 252 in^2
Now for the top and bottom.
3in * 14in = 42 in^2
3in * 14in = 42 in^2
= 84 in^2
And now for the left and right
9in * 3in = 27 in^2
9in * 3in = 27 in^2
= 54 in^2
Finally we can add them all together!
252 in^2 + 84 in^2 + 54 in^2= 390 in squared.