20/09/20 00:06:03.37 UrPOHew+.net
> ai=31.20194
> ak=29.91611
> bi=24.08889
> bk=32.89972
> u=pi/180
> A=c(cos(ai*u)*cos(ak*u),cos(ai*u)*sin(ak*u),sin(ai*u))
> B=c(cos(bi*u)*cos(bk*u),cos(bi*u)*sin(bk*u),sin(bi*u))
> AB=sqrt(sum((A-B)^2))
> d=843
> # asin(AB/2)*2*R=d
> R=d/(asin(AB/2)*2)
> R
[1] 6366.11
> 2*pi*R
[1] 39999.45
>