Drawing Arc Segments

f the Opening Section, Ground Surface and Truncation Surface boundary includes a circular arc segment (e.g., a curved roof), or is a full circle (e.g., a circular tunnel or shaft), then you can easily create an arc segment or circle while you are adding an Opening Section or Ground Surface, as follows:

• Drawing an Arc
• Drawing a Circle

Drawing an Arc

Select the point where you wish to begin the arc, then:

1. Select Arc from the right-click menu, OR type a followed by ENTER in the prompt line.
2. Select the Arc Definition Method and the Number of Segments in the arc.
3. Select OK.
4. You will then be prompted to enter the consecutive points as defined in the dialog.

Drawing a Circle

1. Enter i in the dialog and press Enter.
2. Select the Circle Definition Method and Number of Segments.
3. Select OK.
4. Follow the instructions given on the left of the prompt line.