You have an aquarium in the shape of a rectangular prism. The base is 4 feet by 3 feet. The height is 2 feet. How many square feet of glass were used to build the aquarium? (The top of the aquarium is open.)
Since it is about only the outer part of the aquarium which is made of glasses we need to calculate the total surface area.
Surface area of the base = 4*3 = 12 square feet
Surface area of the shorter length of wall = 3*2 = 6 square feet since it has another wall in opposite side. It has to be multiplied with 2. 6*2 = 12 square feet
Surface area of the longer length of wall = 4*2 = 8 square feet since it has another wall in opposite side. It has to be multiplied with 2. 8*2 = 16 square feet
Therefore the total surface area that need to be covered with glasses 12+12+16 = 40 square feet
