The Rossi family wants to install new tiles on the floor on their kitchen. The tiles they plan to use are 3 in x 3 in squares. The floor space to be covered is shown in the diagram below with measurements given in feet. How many square tiles will the Rossi family need to cover the kitchen floor?
The measurements are 21 feet, 15 feet, 6 feet, 3 feet, 9 feet, and 6 feet. What I did was that I added all the measurements and it came up to 60. I divide it by 3 and it came up to 20. Is this right?