"There aren't 360 Degrees in a Circle"

A. Proof from a 180 degree angleMy opponent concedes that a straight angle has 180 degrees. Note that from this it is trivially easy to prove that there are 360 degrees in a circle.I can produce an illustrated proof. Here is a straight angle of 180 degrees. My opponent agrees with this: Let's now add two such angles together: We obtain a full angle, which is a circle. And we can conclusively deduce the amount of degrees in this circle: 180 degrees + 180 degrees = 360 degrees.Let's this be an additional, 3rd proof, which must be negated by my opponent.B. Rebuttals1. My opponent is ignoring my rebuttals in the previous round.My opponent again conflates the angle terminology. Please note that I am not arguing about how many degrees there are in the internal angles of a circle. I have already discussed this in the previous round, and I still maintain that this is completely irrelevant to the resolution that we have. My opponent must produce an argument, which would support his claim that there are not 360 degrees in the central angle of a circle.Frankly, I am tired of this back and forth arguing about internal angles. It is completely unnecessary and irrelevant, and I find it puzzling why my opponent completely ignores this fact. I will just refer to my arguments in the previous round, as they are sufficient to completely negate whatever my opponent stated in this current round.2. Regular polygons have a central angle of 360 degrees as well. My opponent seems to think that the circle cannot have a central angle of 360 degrees, because that would mean that other regular polygons would also have a central angle of 360 degrees. Quoting him, "We are taught to imagine the central angle takes the form of a circle, when in reality it can be any polygon"This is indeed true. The central angles of other polygons may also be deduced similarly. They are equal to 360 degrees, because they can be subtended by complete arcs. Here are a few examples: If we assume that a circle has a central angle of 360 degrees, which, I believe, I have successfully shown during this debate, then by simply superimposing other polygons onto that circle we can see that their central angles are also 360 degrees. The type of regular polygon itself doesn't matter - it can be a triangle, a square, a hexagon etc. If we take its central angle, it is still 360 degrees.My opponent keeps referring to the internal angles of these polygons. Please note that, again, those angles are completely irrelevant and any arguments by my opponent discussing only these internal angles should be ignored. 3. My opponent misunderstands the nature of definitions.My opponent (again) accuses me of relying on definitions, which he believes are questionable and arbitrary: "my opponent relies heavily on definitions, which he assumes to be true because the Babylonians assumed them to be true." I must again reiterate my stance of this, which I have analyzed in detail in the 2nd Round, and which I also restated in my 3rd round. Definitions cannot be true or false. They are arbitrary constructs of Mathematics, which help us deduce real knowledge. A degree was defined as a 360th part of a complete circle, therefore a degree is the 360th part of the circle. This definition has been accepted by mathematicians, and it means exactly what it means. If my opponent prefers to use other units for angle measurement, he is free to do so: he may use radians, gradians, minutes, seconds, turns - whatever. But that doesn't actually make any difference to what a degree is, nor does it challenge any of my original arguments. I ask my opponent to acknowledge that the arbitrariness of a degree has no impact on this debate.4. More bare assertions by my opponent. My opponent asserts that:The only way it can make sense for a circle to have 360 degrees is if: a) circles do not have an internal angle, or b) the internal angle of a circle is 360 degrees.Note that the whole premise is false, because my opponent does not realize that central angles and internal angles are completely different concepts. I have shown that:a) Circles have infinite internal angles of 180 degreesb) Circles have a central angle of 360 degrees.I must once more emphasize that my opponent's argument makes no mathematical or logical sense.My opponent also asserts that the internal angles of a circle sum up to 180 degrees. He uses a very dubious and mathematically incoherent reasoning:"When there is a flat angle 179.9...(or 180) and an infinite number of angles of 180 degrees, there are no other sides! This is why the sum of interior angles would be 179.9... or 180 degrees, and why a circle has 179.9... degrees, rather than 360 degrees."I see no justification for these bare assertions. My opponent states that a circle has just only one side, and makes a false conclusion about internal angles of a circle.This is problematic for several reasons:a) This debate is not about the internal angle of a circle (yet another conflation of the terms Central angle and Internal angle).b) My opponent completely ignores my proof in the last round, which shows that a circle has infinite sides (or edges).Conclusion thus farMy opponent has virtually produced no arguments at all during this debate. All of his attacks were either based on:a) Internal anglesb) The arbitrariness of definitionsI have shown that both (a) and (b) are completely irrelevant to this debate. He has not produced any reasons why a circle does not have a central angle of 360 degrees. Nor has he shown why my arguments fail.My opponent still has the last round, and I will give him one more shot at producing a logically justified argument. For now, I believe that my case is clearly better here.