JavaScript must be enabled in order to use this site.Please enable JavaScript in your browser and refresh the page. To Add an Extension Line to a Dimension Element Do one of the following: In the Misc(ellaneous) Dimensions toolbox, select Insert (Dimension) Vertex — its tooltip reads "Insert Dimension". orIn the Modify toolbox, select Insert Vertex . Select the dimension element. Enter a data point to position the end of the extension line. Inserting an extension line Parent topic: Insert (Dimension) Vertex