find the side of a regular circumscribed octagon given a circular radius of 336.58 m

We can find this using the Law of Sines

 336.58 / sin(67.5)  = s / sin(45)      where s is the side length  ... solving for s, we have

s = 336.58 * sin (45) / sin(67.5) = about  257. 6 m