SphericalAngle
SphericalAngle[{θ0,ϕ0}->{{θ1,ϕ1},{θ2,ϕ2}}] gives the signed angle in radians between the great circles through point {θ0,ϕ0} and points {θ1,ϕ1} and {θ2,ϕ2}.
SphericalAngle[p->{q,r}] gives the unsigned angle for points p, q, r of the form {θ1,θ2,…,θn-1,ϕ} on an n-dimensional hypersphere.
SphericalAngle[p->{{q1,r1},…,{qn,rn}}] gives a list of angles between the great circles from point p through points qi and ri.
SphericalAngle[{p1,…,pn}->{{q1,r1},…,{qn,rn}}] gives a list of angles between the great circles from point pi through points qi and ri.
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