> In the old days, in the infancy of calculators and my surveying experience, just about all miscalculations could be tracked down to forgetting to convert an angle to DMS, converting it twice, or going the wrong way.
>
> What are your field angles turned in the field?
Pretty sure I did not do that (at least not this time!)
There are only two...The ones shown on the sketch, as follows:
B-A-C = 89?59' 47.5"
A-C-E = 179? 20' 30"
These are each doubled, face left and right.
C-E-A is calculated, as shown on the sketch, by my software calculating the call between E and A.
The internal angles = 180?00'00.5", which I believe is a rounding error, and not a factor.
Those two are the angles I calculated from the sketch, but checking back to the field notes, do they match?
Making assumptions, it appears you sat on A with backsight on B and attempted to turn the record angle of 90 degrees and set point C. Moved ahead to C and turned a discovery angle to E. Pretty much proves that the field angle BAE is not 90 degrees. Your proposed "check" will prove it.
Oh, meant to mention that the calculation of the interior angles is meaningless because one or more of the angles is/are calculated. Those angles would be the result of subtracting from 180.
> Those two are the angles I calculated from the sketch, but checking back to the field notes, do they match?
>
> Making assumptions, it appears you sat on A with backsight on B and attempted to turn the record angle of 90 degrees and set point C. Moved ahead to C and turned a discovery angle to E. Pretty much proves that the field angle BAE is not 90 degrees. Your proposed "check" will prove it.
That's my hope.
Also, correct about the sum of the interior angles. Unless they were all measured, it's meaningless.
> RFC-
>
> How about using stadia ?
>
C'mon! That's SO last June! I did that until I sold my Topcon AG-2 optical theodolite for twice what I bought it for and moved to a nearly as ancient anti-dilluvian Topcon Digital Theodolite, which I sold for twice what I bought it for (after putting a new Ni-Cad pack in it), and replaced it with and almost as old Topcon Total Station, which I'm currently awaiting back from being calibrated.
I'm still trying to decide whether looking at the Philadelphia Rod at 350' made my eyes water more than the whole cosine squared math that followed. I'm on the next chapter of Davis Foote and Kelly!
You might say that my educational venture has covered the "History of Surveying" from Ptolemy to the present time.
Thanks for asking though!:-)