Say that in an edit session I create a line of an exact length entered by keyboard - say 10'
If I later measure that line using the measure tool, snapping to each end of the line, it reads 9.99998'
Then when I check the Attribute Table immediately after completing the line, I find that the line length is 9.99998'.
This is an actual example I just tried, but it it seems to be consistent with all such measurements. They're all off - always less than what I entered as far as I can tell - by a small amount.
Now, I realize this is a very small difference, but shouldn't the editing tool build a line that is exactly 10' if that is the length I enter, and then shouldn't the measure tool "measure" the line to be 10' if that is the length I entered when creating the line?
What is going on here? And although for what I am likely to be doing it doesn't matter, is there a way to prevent this.
To clarify: I create the line in an ArcView edit session by clicking where I want the line to start, then right clicking and selecting "exact length" to type in the length of the line I want to create. I type in 10', and the next node is dropped, in theory at least, exactly 10' from the last point. Then I click F2 to complete the drawing. When I check the attribute table it shows that that the segment is 9.99998' rather than the 10' I specify. I first noticed when I was using the measuring tool - snapping at the beginning and the end of the line. I'm not exactly sure how I could clarify the more.
I am using ArcView 10.1 SP1 Data frame and data are both NAD_1927_StatePlane_New_York_Long_Island_FIPS_3104. Data are created and stored in a File Geodatabase. Not sure what the tolerances are at the moment.