Chapter 2 Creating Primitives and Composites 43 Copyright Goodheart-Willcox Co., Inc. For example, suppose a parking lot is being repaved. You need to calculate the surface area of the parking lot to determine the amount of material needed. This total surface area excludes the space taken up by planting dividers, sidewalks, and lamp- posts because you will not be paving under these items. If the parking lot and all objects inside of it are drawn as a region model, the MEASUREGEOM command can give you this fi gure in one step using the Object option of the Area option. When the Area option is used, the calculated area is highlighted light green. Depending on the number of smaller regions inside the large region, the highlighting may appear incor- rect, but the resulting calculation is correct. If a polyline is used to draw the parking lot, all internal features must be subtracted when the MEASUREGEOM command is used. PROFESSIONAL TIP PROFESSIONAL TIP Regions can prove valuable when working with many items: • Roof areas excluding chimneys, vents, and fans. • Bodies of water, such as lakes, excluding islands. • Lawns and areas of grass excluding fl ower beds, trees, and shrubs. • Landscaping areas excluding lawns, sidewalks, and parking lots. • Concrete surfaces, such as sidewalks, excluding openings for landscaping, drains, and utility covers. You can fi nd many other applications for regions that can help in your daily tasks. Exercise 2-6 www.g-wlearning.com/CAD/ Complete the exercise on the companion website. Chapter Review Answer the following questions using the information in this chapter. 1. What is a solid primitive? 2. How is a solid cube created? 3. How is an elliptical cylinder created? 4. Where is the center of a wedge located? 5. What is a frustum pyramid? 6. What is a polysolid? 7. Name at least four AutoCAD 2D entities that can be converted to a polysolid. Figure 2-28. Once the circular regions are subtracted from the rectangular region, they appear as holes. This is clear when a shaded visual style is set current.