Can a graphic line with a specified length be drawn directly in ArcGIS Pro?

No, it is not possible to draw a graphic line with a specific length directly on the map in ArcGIS Pro. By default, the size of a graphic line can only be configured in the Element pane after the line has been drawn. The Measure tool can then be used to verify the configured length. For more information, refer to ArcGIS Pro: Work with graphic elements in a map.

Alternatively, use map notes. Before finishing a line, right-click the unfinished segment and select Change Length, then specify the exact distance and unit. The on-screen Constraints setting on the status bar at the bottom of the active map can also be used. However, these methods are inefficient when many lines must be created. Adjusting each graphic line individually requires additional steps, and map notes create feature-based lines rather than graphic lines.

As another alternative, the reference grid can be configured to determine approximate lengths and visualize distances while sketching. Refer to ArcGIS Pro: Use the reference grid and ArcGIS Pro: Configure the reference grid for instructions.