432 AutoCAD and Its Applications—Basics Copyright Goodheart-Willcox Co., Inc. The Area option includes options that allow you to calculate the sum of multiple areas during a single operation. Before selecting corners or an object, activate the Add area option and defi ne the fi rst area by picking corners or using the Object option. Continue adding areas as needed, or use the Subtract area option to remove areas from the selection set. AutoCAD calculates a running total of the area as you add or remove areas. Figure 15-11 shows an example of using the Add area and Subtract area options of the Area option in the same operation. In this example, select the Add area option, then select the Object option, and pick the rectangle (polyline). Press [Enter] at the (ADD mode) Select objects: prompt to continue. The area and perimeter of the rectangle and a total area appear. Then select the Subtract area option to enter SUBTRACT mode. Select the Object option and pick the circles to subtract the area of the circles from the area of the rect- angle. The area and circumference of each circle appear, along with the total area of the rectangle minus the total area of the subtracted circles. Press [Enter] at the (SUBTRACT mode) Select objects: prompt to continue. Press [Enter] to display the total area and return to the MEASUREGEOM command prompt. Figure 15-9. Measuring the area of a room on a floor plan. Use the Area option of the MEASUREGEOM command to calculate the area encompassed by selected corners. Fourth point Third point Second point First point Sixth (final) point Fifth point Figure 15-10. Values returned for common objects when you use the Object option. Object Values Returned Polyline Area and length or perimeter Circle Area and circumference Spline Area and length or perimeter Rectangle Area and perimeter