# How Do I Find A Surface Area Of A Room?

Multiply the length of the perimeter of the room by the wall height to get the wall area. Multiply length times width for the area of a rectangular shape such as a ceiling or floor. Usually, you are interested in square feet, so the measurements need to be expressed in terms of feet.

Example

Suppose you have a room that is 10' by 12' with a ceiling that is 7' 10" above the floor. The perimeter of the room is 10' + 12' + 10' + 12' = 2(10' + 12') = 2*22' = 44'. The height in feet is 7 10/12 ft = 7 5/6 ft. (An inch is 1/12 ft.) The total wall area is

(44')(7 5/6') = (44*7 + 44*5/6) ft2 = (308 + 36 2/3) ft2 = 344 2/3 ft2

The ceiling or floor area of the rectangular room is the product of length and width,

(10')(12') = 120 ft2 The total surface area of the room is the sum of the areas of ceiling, walls, and floors:

120 ft2 + 344 2/3 ft2 + 120 ft2 = 584 2/3 ft2.

Of course, if you are figuring for paint, you just add up the areas that will be painted.

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www.ehow.com  Here's how to find the surface area of 3D objects.
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Formulas for the area of many polygon, circular, and elliptical shapes have been developed. To find the area of such a shape, you determine the appropriate dimensions of the shape, match them with the variables of the formula, and evaluate.

For many regular solids, formulas for surface area have also been developed. For solids having faces in the shape of a polygon, it is the sum of the areas of each of the polygon faces. A regular tetrahedron, for example, has 4 congruent triangular faces--so the area of the surface is the 4 times the area of one of the faces.

For solids with curved surfaces, formulas have been developed for a few: Cones and sections of cones, spheres and sections of spheres, cylinders. Certain elliptical shapes also have surface area formulas that have been worked out.

If you can write an equation for the curve that generates the surface, calculus may help you determine the equation for the surface area.

What constitutes a suitable method of measurement of surface area depends on what you are measuring and how accurate you need to be. Measuring the area of a snowflake requires different methods than measuring the area of a battleship. Finding the surface area of the leaves of a tree is a different proposition from finding the area of your living room wall (unless you live in a tree house).

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