posted by Sean .
A square plot of land has a building 60ft long and 40ft wide at one corner. The rest of the land outside the building forms a parking lot. If the parking lot has area 12,000ft^2, what are the dimensions of the entire plot of land?
The answer is 120ft by 120ft. I just don't know how to get to the answer. I was thinking (x+40)(x+60)=14400. because parking lot area + area of the building = 14400. So I was trying to find the dimensions with the area given.