Because Revit has no such thing as a "Polyline", you can't select one object and see its total length. And such tasks happen all the time. This is why the "Lines length" plugin was developed. This plugin will allow you to get the total length of the selected elements, such as
Families based on a line
1. Choice of elements
2. Launching of the plugin
3. Displaying the result
As a result, the appeared window displays information about the total lines length, communications or other families on the basis of the line.