Measure Radius

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:

Measurements of referenced perspective saved views are not supported.

(Technology Preview) Use reference scale allows you to measure in true model units while measuring in a sheet. This setting is off by default.

Note: This setting is only applicable in the Sheet models.

Key-in: MEASURE RADIUS

Note: To dimension an element's radius, use the Element Dimensioning tool.