Randy is building a cube-shaped doghouse with four faces. he is leaving one face open as a door, and one face open to the ground. the doghouse will be 4 feet long. what is the total surface area of the walls and the top of the doghouse?

be sure to include the formula for surface area.

show how to modify the forumla for surface area to meet the needs of this problem.

show all of your work, including your final answer with the correct units