Need math word problem help please!! Thank you!

Question

A square plot of land has a building 70 ft long and 60 ft wide at one corner. The rest of the land outside the building forms a parking lot. If the parking lot has area 5,800 ft2, what are the dimensions of the entire plot of land?

Answer 1

add the parking lot area to the area of the building (length x wide).   so find the area the building takes up and add the amounts together.