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

Top right since it passes vertical line test

1. 0.3 •4 is the same as 4 groups of 0.32. 7•0.8 is the same as 7 groups of 0.83. it increases by 0.5 every time, so 0.5x4 it increases by 0.9 every time, so 0.9x5. 0.9•12=10.86. 0.47•5=2.35i can finish the next ones in a separate post