Does anyone use plain ol' triangles anymore? I remember when triangle solvers were a regular part of standard field surveying software. Over the years those solvers faded away to nothing. I used to use a SAS solver to calc sides of a building. How about using a SSS solver to find missing angles in a triangular-shaped lot? Back in the nineties the old timers used to complain about us using COGO instead of plane geometry. It was a sign of the times.
I scratch all over my work orders solving plain ol' triangles.?ÿ It drives my help nuts.?ÿ He's always saying, "The data collector will do that...here let me show you".?ÿ I just solve a few triangles and then add or subtract a couple of distances from existing point coords to get new points.?ÿ I'm just about as fast as that damned DC because we've raced to see who can get the answer first.
Just the other day we needed a point where the tangent R/W intersected a 50' R/W curve around a cul-de-sac.?ÿ The sac was a 50' R/W and the distance from center line to the tangent R/W was 30'.?ÿ That one was easy as it made a "30,40,50" right triangle..and away I went with my pencil and paper.?ÿ It took my helper 3 or 4 minutes to come up with the same numbers.
Triangles are our friends.
Triangles are our friends.
Yes they are. ?????ÿ
As simple as they are, we ask a lot of them, and they provide.
I have an app on my iPhone that works really well - Trig Solver. Its right next to my Slide Rule app...
The old "Rite in the Rain" books had not only the Trig Formulae and triangle solutions, but a brief Reduction to Horizontal and a Slope Staking chart. .?ÿ Older yellow books had Curve Tables and Trig Functions.?ÿ The new ones, crickets.?ÿ
I don't like the description of what the app solves for. I've never heard of a regular triangle, so I looked it up. A regular triangle?ÿis one for which all sides are congruent?ÿand all?ÿinterior angles?ÿare congruent. That is clearly not always the case. I prefer using the term oblique triangle when a triangle is not a right triangle.
Speaking of geometric shapes, the PBS Kids games are addicting. They also have a build a flood proof city game that is pretty entertaining...
https://pbskids.org/designsquad/games/fidgits_rescue/
Curve Tables and Trig Functions.
The old K&E, now Elan field books have curve tables, but unfortunately they are approximations to the chord definition.?ÿ I haven't seen the Ritei nt he Rain books - are they the same?
Two things my High School Trigonometry teacher pounded into our brains was: "a" squared + "b" squared = "c" squared?ÿand?ÿ
Length of curve = (Pi x Radius x Delta)/180?ÿin my case, I actually remembered, and used them ever since, and thats been a looong time.
Why she taught us about circular curves in a trigonometry class is still a mystery to me.
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Two things my High School Trigonometry teacher pounded into our brains was: "a" squared + "b" squared = "c" squared?ÿand?ÿ
Length of curve = (Pi x Radius x Delta)/180?ÿin my case, I actually remembered, and used them ever since, and thats been a looong time.
Why she taught us about circular curves in a trigonometry class is still a mystery to me.
????
One formula in particular that has stayed with me all these years comes from the days of laying out curves with a chain and transit:?ÿ the chord length is equal to twice the radius times the sin of the deflection angle or 2R(sin D) . After all, the chord length was what we really needed to know after we figured the deflection.
I have a copy of Survey Solutions for HP41. And SSS SAS ASA AAS SSA are alive and well.
I have that in HP41-iPhone App as well.
I also have COGO on my 41s. Perfect pairing for T2 and HP3805 traversing.?ÿ
@flga
She taught curves because they can easily be defined as triangles. There are very few day to day survey tasks that can't be efficiently accomplished with elementary algebra and basic trig.
I have a copy of Survey Solutions for HP41.
From D'Zign?
When I started as party chief, there were no affordable calculators and I either used DMD sheets and a 7 decimal trig fan to solve traverse closures, boundaries, areas, or else I would use triangles for the really obscure shaped tracts to compute values.
My journal from many years ago, when I rotated through location survey with FDOT as part of my training in civil engineering. Those were the good old days when I was starting to move up in the world and I could see a rosy future.
Tuesday 8 June 1965. I impressed Jim Harris no end by calculating (in my head) how much the base would be with a hypotenuse of 12.67 at 5?ø34??49?. I spotted a shortcut and within seconds said 12.62, no, make it 12.61. Jim told the guy with the tables, ??Calculate it.? Louis Culbreath talked to me later and said Harris couldn??t get over how I did it.
I applied for a job with a county survey dept in 1985.
There was a panel of 4 giving the interview. They asked me for formulae for obliques. Laws of sine and cosine. And long hand curve calculation?ÿ
Would that be part of a job interview today??ÿ
@bill93 My book number 233, from 1990 is a Rite in the Rain, Transit Book No. 300F.?ÿ In it is a section in the back of the book labeled Curve Tables, where all the math formula and examples that you would need are located along with six pages of (Table I) tangents and externals for 1 degree curves, chord definition, to the nearest 10 minutes of interior angle.?ÿ There is also trig functions for angles to 10 minutes and even a table to convert minutes in decimals of a degree.?ÿ A plethora of information.?ÿ Sadly, this information if you needed it, was only in that run of field books because by the time we got to book 244, these tables were gone.