I don't know if I'm doing this proof right. But, there are 2 ways to figure out an arc length of a circle s=rθ, and finding the circumference of a circle and multiplying that by the ratio of the angle of the arc/360.
So here is my proof, let's start out with the latter method of finding the arc length.
1. 2*π*r((θ*(180/π))/360) = s
Ok, the part where I take theta and multiply by 180/π is to convert degrees to radians. And then I take that and divide by 360 degrees.
2. 2*π*r(θ*(180/π)*1/360) = s
3. 2*π*r(θ*(1/2π)) = s
4. 2*π*r(θ/2π) = s
5. 2*π*r*θ/2π = s
6. r*θ = s
So, that's my proof. Is there something wrong with the proof?
Circumference * ratio of angle arc/360