You would start off by finding the base, which is 18*12. That equals 216 meters squared, you multiply that by 2 to get the surface area of your 2 bases. That equals 432 meters squared. To find the surface area of the sides (on the left and right side), you would use the equation length times height. To plug in the numbers, you use 12*4, that is 48 meters squared. There are 2 sides, so multiply by 2, to get 96 meters squared. To find the last side, you take length times width, plug in the numbers. Those numbers are 4*18, which equals 72 meters squared. Once again, there are two sides, so you multiply by 2, to get 144 meters squared. Next, as the final step, you add up all of the final numbers. They are: 432+96+144 which equals 672 meters squared.
