Center Dimensions (2D)
Insert 
Dimension Center
(Sketch/Sheet Level)
Use these commands to create 2D radial dimensions at the sketch and drawing sheet level. You can create standard, diametric, broken, big and leader radial dimensions.
Use this command to create a center mark at an arc or circle.
Use this command to place a centerline through a circular pattern such as bolt holes. Select the hole center locations and then middle-click to add the centerline. Optionally, you can define the center of the centerline, use and arc or a circle (open or closed centerline) and set the center mark type and length.
Arc - Select the arc to dimension.
Break point - Specify a reference point to locate the break.
Origin - Specify the location of the dimension text.
Center
Use this option to rotate the center line/mark toward a selected point.
Arc/Circle
Use this option to create a centerline for a Circle or an Arc.
Rotation (for Center Line/Mark only)
Use this option to rotate the center line/mark toward a selected point.
Attributes (Center Line/Mark commands only)
Enter the size of the center mark. It will be applied when the center mark is toggled on (see above). You can also select from the three center mark types shown below:
