Sketcher > Dimensioning Sketcher Geometry > Working with Dimension Tools > Normal Dimensions > To Create a Total Included Angle Dimension
  
To Create a Total Included Angle Dimension
1. Right-click in the Sketcher window and choose Dimension from the shortcut menu or click Sketch > Normal.
2. Select the entity to dimension.
 
* The entity must be linear and cannot be parallel to the centerline.
3. Select the centerline.
4. Select the entity again and middle-click to place the dimension. The dimension is created.