To Insert a Dimension for an Arc
1. Click
Annotate >
Insert >
Dimension. The
Select Reference dialog box opens.
2. Select
on entity, or
tangent point reference option on the
Select Reference dialog box.
3. Select an arc. The ghost image of the dimension appears with the radius format.
4. Right-click and select Diameter, Angular, or Arc Length as the type of the dimension for the arc.