What is one degree (angle measurement)? I know that we calculate one second using atomic clock, one kilogram using Planck's constant, one meter using speed of light but how do we define one degree? If someone know how degrees were calculated in ancient times, please tell.
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$\begingroup$ That is not calculated. It is not measured. It is an arbitrary definition. They just liked the number 360. $\endgroup$– naturallyInconsistentCommented May 9 at 11:07
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1$\begingroup$ Please clarify your specific problem or provide additional details to highlight exactly what you need. As it's currently written, it's hard to tell exactly what you're asking. $\endgroup$– Community BotCommented May 9 at 11:09
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$\begingroup$ Suppose we don't have any angle measuring tool and we are given a triangle with measurements of its side then how can we calculate the interior anglesof th triangle or in general any geometrical shape? $\endgroup$– Payal PayalCommented May 9 at 11:10
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$\begingroup$ Have you learned trigonometry? $\endgroup$– Marius Ladegård MeyerCommented May 9 at 11:19
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1$\begingroup$ This is better asked in the history of science site: hsm.stackexchange.com $\endgroup$– DanielCCommented May 9 at 11:47
2 Answers
One degree is defined as $\frac 1 {360}$ of a full revolution. If you are creating a measuring instrument it is probably more convenient to define it as $\frac 1 {90}$ of a right angle or $\frac 1 {60}$ of the angle of an equilateral triangle, since there are simple geometric methods of creating a right angle or an equilateral triangle.
So you draw a circle, measure off a chord that is equal in length to the circle's radius - this gives you an angle of $60$ degrees - then take a piece of string and measure the length of this $60$ degree angle around the circumference of the circle. Divide this length by $60$ and you can mark off an angle of $1$ degree on the circle.
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$\begingroup$ Does our modern instruments used to measure angles are based on this principal or not? $\endgroup$ Commented May 9 at 16:59
the 360-degree circle has its origins in Babylonian astronomy combined with the need for a consistent bureaucratic calendar in the Babylonian state. As a bonus, it has factors of 2, 3, and 5, yielding convenient integer answers for subdivisions of the circle.
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$\begingroup$ Then I do not know what it is you want. $\endgroup$ Commented May 9 at 23:04