Again, a mathematical proof doesn't have anything to do with reality.
You just asked for a proof. Now that it has been given to you, you are making a blanket declaration that mathematical proofs have nothing to do with reality?? What??? If you don't think it has to do with reality, then go test it in reality, like I have stated numerous times. Your entire argument seems to be based on incredulity that angles can be measured from our point of view, which is ridiculous. Stop whining about the ancient Greek mathematicians and go test it.
I do not wish to continue this discussion.
Cognitive dissonance starting to get uncomfortable?
Come on, didn't you pass middle school algebra? Look up the definition of a mathematical proof:
https://en.wikipedia.org/wiki/Mathematical_proof
In mathematics, a proof is a deductive argument for a mathematical statement. In the argument, other previously established statements, such as theorems, can be used. In principle, a proof can be traced back to self-evident or assumed statements, known as axioms, along with accepted rules of inference.
Yes, I know what a mathematical proof is. Yes, I am aware that if you start with bad assumptions then the conclusion may not agree with reality, just like any other kind of proof. Obviously.
Let's be specific. This is what I am arguing is true:
Given objects at locations A, B, and C, with distances between the objects given by
a and
b. The angle
α can be measured by a person at location A. This angle will be equal to
arctan(a/b).
There are several ways of measuring this angle, all of which should agree:
1. Using a theodolite.
2. Stretching a string between the objects and using a protractor.
3. Pointing two sticks at the objects and measuring the angle between them with a protractor.
4. Measuring the distance between the objects in a picture, and calculating the angle based on the FOV of the camera. (Approximation based on the distortion of the camera.)
Forget the mathematical proof if you want. This is common sense to most people, but if it isn't common sense to you, then go test it. It is easily testable in reality.