Use this option to define various types of polygons (line, arc) graphically or by typing the coordinates in the appropriate edit fields of the Section Definition dialog.
Access the option by:
- Selecting Tools layout > Section Definition.
- Clicking Contour menu > Polygon, or clicking
on the toolbar.

Note: If a contour is defined by lines, select Fillet radius in order to fillet the contour corners.
If you select Relative and then define a polygon, coordinates of the next vertex are calculated with respect to the position of the preceding vertex. If Relative is cleared, coordinates of polygon vertices are given in the adopted coordinate system.
When defining a thin-walled section, the following options are also available:
- Thickness - type the thickness value of a thin-walled section.
- Icons:
- Defines the line of the section as the section middle line.
- Defines the line of the section as the section external line.
- Defines the line of the section as the section internal line.