Measurements with Autocad?

Draw shape witn POLYLINE command, pick on vertex, at last vertex digit C for close, Autocad draw line and connect first vertex with last vertex, your polyline is closed

Command: POLYLINE (return)

First point: (pick on point)

To point: (pick on point)

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To point: (pick on point)

To point: Close (return)

With command AREA you pick on polyline and you have Area

Or pick on polyline, press right mouse button and select Property from list, this show panel property where you can see at Area or Lenght (perimeter) field

With DIST command you can measure lenght of any line on drawing >> for take point exactly you set osnap mode

Digit DDOSNAP (or OSNAP) and check box ENDpoint, INTersection point, then press OK and exit from dialog

Press F3 key you can commutate state for osnap ON / OFF, press F3 and set to ON

Now you can measure distance with DIST, when you put cursor mouse near at point, you see a mark (cross or box yellow) >>> this means that when you clik on left mouse button you take point with max precision, if you not use osnap (ie not see yellow mark) you can't take point of line but take a point near to vertex line >> in this case you have error in a distance

there is an icon that looks incredibly like a ruler. click on that, (be certain your ortho is on)and click each and each factor. If the length doesnt happen on the reveal, look interior the backside left corner of the reveal....if this doesnt help it truly is a deeper difficulty alongside with your settings...