An arc can be defined in several ways: by points, by centre, radius and arc, etc. The various properties are displayed in the window that appears on the right.
Changes to certain properties can be accommodated in different ways, for example by changing the radius or the start/end point. The Fixed centre.

Parameters
Radius | Constant distance between the centre of the circular curve or arc and any point along its circumference. |
Start/end angle | Angle of the start or end point relative to the centre. |
![]() | Round angle |
Tangent to Prev./Next | Changes the start or end angle so that the arc is tangent to the previous or next entity. |
![]() | Increase/decrease angle |
Fixed centre | Determines the consequences of a change to the radius or angle. |

