"There aren't 360 Degrees in a Circle"

The definition of a degree I gave was from the Oxford English "mini" dictionary, I apologise for not making this clear. The full definition is what you have said, that is a unit of measurement of angles, one ninetieth of a right angle or the angle subtended by one three-hundred-and-sixtieth of the circumference of a circle.I do not question that 360 degrees are used to represent the number of degrees in a circle since there are full circle protractors which display 360 degrees.Suppose I took a flat bit of wood with a length of 10cm, then added 15 markings spaced equally along the length and declared it has 15cm. How long is the ruler I made? I'm sure you will agree that it is 10cm long. It can only be 15cm if centimetres were not already a unit used for measuring distances. I'll give another example to make this point clear, if someone along time ago said 'the Sun is 360 miles away' and it was accepted because no-one thought it is possible to calculate, but then someone worked out that the Sun is 90 million miles away, we wouldn't just say that a mile is equal to 1 mile and also 250,000 miles. Someone would be wrong! It's the same with degrees. In order to create an instrument for measuring angles you'd first need to define the number of degrees in a straight line. Once an angle has been defined it is possible to calculate the number of degrees in every polygon including a polygon with infinite sides i.e. a circle. A triangle has 180 degrees because as you can see from the diagram below the angles A, B, and C add up to 180 degrees. Adding a side to this polygon will give the next polygon (a square) 180 degrees, adding a side to a square to make a pentagon means I must add 180 degrees to 360 giving 540 degrees, and you get the pattern. Repeatedly adding 180 degrees in an attempt to calculate the internal angle in a circle will give an infinite sum of angles, but a circle only has one side and thus one angle, so it can't have an infinitely large angle. Using the method used in round 2 will give the correct answer, in my view and shows that the definition of a degree defined by the method does not lead to the conclusion of a 360 degree circle. s://www.mathsisfun.com...; alt="Proof the angles in a triangle add to 180" /> Image source: https://www.mathsisfun.com...You will notice that angles will be enclosed by an arch unless they are right angles, this doesn't prove there actually are 360 degrees in a circle, the only thing it proves is that we are taught to accept this idea.The only calculations provided by my opponent in round 1 were conversions, which do not prove anything. He does use an equation to show that the internal angle of a circle is 180 degrees, not 179.9... degrees, but fails to show how 360 is derived. Pi iself is not needed to calculate the angle of a circle, the method used is, which is why I believe the Babylonians made up the number of degrees in a circle. I challenge my oppoent to prove there are 360 degrees in a circle without making any assumptions, accepting only that there are 180 degrees in a straight line. I also ask my opponent to prove that the central angle as he calls it is of a circle and not a square Many thanks