Enla, engineer's Length and Area add-in, is designed to make reading and manipulation with length and area easier.

Select lines, polylines, circles or hatches in Autodesk® AutoCAD® and have their length and area values in a list. 

From this point you can:

• select  all or some items in list to see cumulative values
• click on "copy" icon to copy  selected values to clipboard
• click on "zoomto" icon to zoom  to that object in AutoCAD
• pin selected items to track  object no matter of current AutoCAD selection, and watch values change as you change object's dimensions
• add a  tag  on selected items to make easy manipulation once values are pasted to, for example, Excel®
• choose round and scale options and the way values are shown (system locale or different)
• insert values in drawing as a text or field (where applicable), next to its originating object
• insert values as  table
• insert as block  and populate attributes or dynamic properties with values
• evaluate custom math expressions 

To evaluate objects, use standard math expressions in formula tab with optional Enla variables

• L = length of object (when inserting as field, not all objects can use it)
• A = area of object (if object has it)
• n = position of object in list
• tag = custom text tag, saved to object in drawing
• cc = incremental value, number of clicks on cumulative button
• Lt = total length of all objects in list
• At = total area of all objects in list
• Ls = cumulative length of selected in list
• As = cumulative area of selected in list 

Examples:

• L * 100 / sum(Lt) = percentage of length in relation to total length
• average(As) = average area of objects selected in list
• L > average(Lt) = 1 or 0, compare how individual L relates to the average length
• ...imagine...