geometry
posted by Courtney .
If you had a room that is 10 foot by 12 foot in the shape of a rectangle, and one gallon of paint covers about 350 square feet, how many gallons of paint would you have to buy if you were painting the walls and the ceiling?

Ceiling: 10 * 12 = 120 sq. feet
You need to know the height of the walls to determine their areas.