This shape would appear to be a rectangular prism.
The lateral area (area of every side except top and bottom) is given by the formula:
LA = ph (perimeter of the base multiplied by the height)
The surface area is then found by adding the LA to the areas of the Bases (top and bottom).
SA = LA + 2B
In your figure:
LA = 18 times 3 = 54 square cm
SA = 54 + 2(14) = 82 square cm
The volume of a right rectangular prism is given by the formula:
V = LWH (length times width times height)
In your case,
V = 7 X 2 X 3 = 42 cubic cm.
Well, on the offchance you can't understand masters' explanation; the easiest way to get the area is just to say: Total surface area = Sum of the areas of each face.
So you've six faces, all rectangles. The area of a rectangle is obtained by just multiplying the two sides.
So, say, the face at the top is 7x2 = 14.
And the face at the bottom will be the same = 14.
The face in front is 7x3=21
As is the one at the back = 21.
The other face you can see is 3x2 = 6.
And the corresponding one that you can't see =6 also.
So the sum of the four squares is 14+14+21+21+6+6 = 82.
The Surface Area is found by adding the areas of all the faces or more simply, if the base is "l" by "w" and the height is "h", then the surface area is given by:
SA = 2(lw + hl + hw)
Another method I already gave you in my earlier post.