Working with Markups > Measurements > 3D Measurements > To Measure Radius or Diameter
  
To Measure Radius or Diameter
1. Click Markup > Diameter. The Measure Diameter dialog box opens.
2. In the graphics area, select the circle to measure. The diameter is calculated, and it appears in the graphics area and in the Results panel of the Measure Diameter dialog box.
When measuring a radius in a 2D section:
If you select an arc, Creo View calculates the diameter of the circle and displays an approximate result.
If you select a geometry that is not an arc, Creo View selects the ends of the selected segment and an additional neighboring segment, calculates the diameter of the circle, and displays it as a local radius. The segments ends used for calculating the local diameter are marked with three dots, in the secondary selection color.
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The Results table specifies whether the radius is local or not.
3. Toggle Measure Radius switch between diameter and radius measurements.
4. Click . The measurement is saved to the annotation set.