To find the surface area of the walls, take the total length and multiply by the height. For a square room that would be 4 * length * height. For a rectangular room then ((2 * length1) + (2 * length2)) * height. For a room of any shape, just set a start point, then measure all along the wall until you end up at the same place, then multiply by height.

For the floor and ceiling, basically the same thing, take length * width and that should be.

If the celing is sloped, or vaulted, then split it into flat areas and add them up. 3D flooring

You measure the with and the length of the room and multiply them , like lets say the room is 12 by 16 feet . You take 12 X 16 = 192sq foot .

The length of a rectangular room is 3 feet longer than its width. The area of the room is 130 square feet. Find teh dimensions of the room