Hi, just back from the beach, as SEANT & eldon were kind enough to point out, a couple of obvious issues.
Issue number one would be that the drawing is not done to 1:1 scale, which is a bad way to start.
In modelspace the drawing should be done FULL SIZE, doesn't matter what you are drawing. Which is why in dimensions
you see units of measure like LIGHT YEARS. Yes even when drawing the SOLAR SYSTEM you would draw it full sized in modelspace.
Yes, that is right, you probably wouldn't print it fullsize, you would scale it to an appropriate size from your paperspace viewport.
Assuming that is not the issue right now. Back to modelspace.
Lastly, if instead of using TEXT to dimension the perimeter in your modelspace, you had just used the current dimstyle,
you would have very quickly recognized that the drawing was not correct.
It seems like you probably have it sorted out by now. You also have some doubled lines in the perimeter.
I would suggest using closed polygons for work like this. All you need to use is the JOIN command with MULTIPLE option to join and then you can CLOSE
your polygon in the properties by selecting CLOSED YES.
Had you drawn a CLOSED polygon, your PROPERTIES or QUICK PROPERTIES palette would have given you the area without
using any commands. As eldon mentioned the area would be in the drawing units (in this case meters) squared.
By entering -DWGUNITS at your commandline you could determine what the drawing units in use in the drawing are.
6 represents METERS, which you will see after you open the DRAWING UNITS dialog box with the -DWGUNITS command.