Creo Options Modeler > References > Fundamentals > Creo Parametric User Interface > The Analysis Tab > Measuring Geometry > Measuring Entities > Using Specific Measurement Types > Diameter > About Measuring Diameter
  
About Measuring Diameter
You can measure the diameter of a cylindrical or conical surface, or a circular edge or curve. You can select a point on the surface to specify the location at which to measure the diameter. When you measure diameter, the radius is also shown.