To Measure Using One or More Reference Entities
1. Click > 
Measure and select a reference entity, or select an entity first, and then click > Measure.
Measure and select a reference entity, or select an entity first, and then click > Measure.The Measure dialog box and a measurement panel open showing the measurements for the selected entity.
2. Click 
to expand the Measure dialog box.
to expand the Measure dialog box.3. Measure, one, two, or three or more reference entities:
◦ One—To measure a different entity, select another entity.
◦ Two—Hold down the CTRL key and select another entity.
▪ A panel for the second entity opens.
▪ A combined panel opens to show the common measurements for both the selected entities, for example, the distance between them.
◦ Three or more—Hold down the CTRL key and select more entities.
▪ A panel for each of the added entities opens.
▪ A combined panel opens that shows the common measurements for all the selected entities, for example, accumulated length.