Jan16 awarded Popular Question Jan8 comment Radians (and angles in general) how do they work? Thanks sir, that was a great help! Jan6 answered Where can I find the old papers of the Math Tripos? Jan5 revised Derivation of the length of an arc formula added 152 characters in body Jan5 asked Derivation of the length of an arc formula Jan4 comment Radians (and angles in general) how do they work? "This correspondence factors through the computation of arclength/radius, similarly giving us a constant measurement (regardless of the length of the arc) for the rotation corresponding to the angle through which we rotated." I was reading this and im just a little confused as to what "correspondence" you refer to, is it (2pi)(r)=c, and more specifically what do you mean by "This correspondence factors through the computation of arclength/radius", i'd appreciate it if you could clear this up, thank you! Jan4 comment How is the Radian measure of angles derived/defined? Thanks, I finally understood! Thanks a lot! Jan4 accepted How is the Radian measure of angles derived/defined? Jan2 comment Just how much proof knowledge is necessary to begin Spivak's Calculus? What are other 'canonical' books if you don't mind me asking? Jan1 comment Radians (and angles in general) how do they work? +1, A really lucid answer, thank you Jan1 comment How is the Radian measure of angles derived/defined? Can you define a radian for me? Please, thanks. Jan1 comment How is the Radian measure of angles derived/defined? Why doesn't s/r tell you anything about the size of the circle? Surely if you put in a large r value it means it's for a bigger circle? I'm sorry for testing your patience, you've cleared so much up for me, I feel I just need to understand one more thing and everything will click into place but I don't know the question to ask.. Jan1 revised How is the Radian measure of angles derived/defined? deleted 2 characters in body Jan1 revised How is the Radian measure of angles derived/defined? added 395 characters in body; edited title Jan1 revised How is the Radian measure of angles derived/defined? added 395 characters in body; edited title Jan1 revised How is the Radian measure of angles derived/defined? edited tags Jan1 comment How is the Radian measure of angles derived/defined? Basically how did we go from 2$\pi =\dfrac {C}{r}\rightarrow \theta =\dfrac {s}{r}$ Jan1 comment How is the Radian measure of angles derived/defined? Thank you for your answer, it cleared up a few things, what I'm having really difficulty understanding is how the formula $\theta =\dfrac {s}{r}$ is derived, as the original equation $2\pi =\dfrac {C}{r}$ isn't talking about angles, it's just talking about the ratio of the circumference to the radius of a circle, where and how did this angle formula come about? Thanks! Dec31 revised How is the Radian measure of angles derived/defined? edited body Dec31 revised How is the Radian measure of angles derived/defined? added 31 characters in body