## Area

For area measurements in water/wastewater operations, three basic shapes are particularly importantâ€”namely, circles, rectangles, and triangles. Area is the amount of surface an object contains or the amount of material it takes to cover the surface. The area on top of a chemical tank is called the surface area. The area of the end of a ventilation duct is called the cross-sectional area (the area at right angles to the length of ducting). Area is usually express in square units, such as square inches (in.2) or square feet (ft2). Land may also be expressed in terms of square miles (sections) or acres (43,560 ft2) or in the metric system as hectares.

A rectangle is a two-dimensional box. The area of a rectangle is found by multiplying the length (L) times width (W) (see Figure 3.4).

Figure 3.4 Area of rectangle.

Figure 3.5 Rectangle for Example 3.45.

## Guide to Alternative Fuels

Your Alternative Fuel Solution for Saving Money, Reducing Oil Dependency, and Helping the Planet. Ethanol is an alternative to gasoline. The use of ethanol has been demonstrated to reduce greenhouse emissions slightly as compared to gasoline. Through this ebook, you are going to learn what you will need to know why choosing an alternative fuel may benefit you and your future.

## Post a comment