Chapter 6 -- ENTITIES Section
ARC

The following group codes apply to arc entities. In addition to the group codes described here, see "Common Group Codes for Entities." For information about abbreviations and formatting used in this table, see "Formatting Conventions in This Reference."

Arc group codes
Group codes Description

100

Subclass marker (AcDbCircle)

39

Thickness (optional; default = 0)

10

Center point (in OCS)
DXF: X value; APP: 3D point

20, 30

DXF: Y and Z values of center point (in OCS)

40

Radius

100

Subclass marker (AcDbArc)

50

Start angle

51

End angle

210

Extrusion direction. (optional; default = 0, 0, 1)
DXF: X value; APP: 3D vector

220, 230

DXF: Y and Z values of extrusion direction (optional)