Used to measure:

• The radius of a circle or circular arc.
• The radius of a cone or cylinder.
• The primary and secondary axes of an ellipse or elliptical arc.
• The radius of a circular segment or axes of an elliptical segment of a complex chain or complex shape.

You can access this tool from the following:

• Ribbon:
• Toolbox: Measure

Measurements of referenced perspective saved views are not supported.