In this exercise, you will define two sections from an existing surface by referencing existing lines in the drawing to define as sections. First, specify EG as the current surface.

1. On the Terrain menu, select Set Current Surface to display the Select Surface dialog box.

2. From the Selection list, select EG, and then click OK.

3. From the Terrain menu, click Sections Define Sections.

4. Enter W-E for the Group Label and AA for the Section Label.

   Use the following steps to specify line AA as the first section line.

5. Use an Endpoint Osnap to select the left end of line AA, and then use an Endpoint Osnap to select the right end of line AA.

   Use the following steps to specify line BB as the second section line.

6. Enter BB for the Section Label, and using an Endpoint OSNAP select the left end of line BB, and then using an Endpoint OSNAP select the right end of line BB.

7. Press ENTER twice.

   Next, process the sections.

8. From the Terrain menu, click Sections Process Sections.

You now have two sections defined from a single surface.