Question

Enya is building a storage cupboard in the shape of a rectangular prism. The rectangular prism has a square base with side lengths of 2.3 feet and a height of 3.6 feet. Use percentage to compare the amount of paint she would use to paint all but the bottom surface of the prism to the amount she would use to paint the entire prism. Round your final answer to the nearest tenth.
Enya will paint
________% of the surface area of the storage cupboard.
PLEASE HELP!!!

Answer 1

To answer this question you would need to find the surface area of this rectangular prism. In order to find the surface area you would find the areas of all six faces. The top and bottom faces would both be square with an area of 5.29 (2.3x 2.3)ft.². All for lateral faces would have areas of 8.28 (2.3x3.6)ft.². Adding these for faces along with the other two faces would give you a total surface area of 43.7 ft.². If you take away the bottom face which is not painted you will have a surface area that is going to be painted of 38.41 ft.². To determine the percentage of this rectangle or prism that is going to be painted, create a ratio of the amount painted to the total amount surface area. Divide these to create a decimal and then converted to a percent. 38.41/43.7=0.879 (87.9%).