IMO Shortlist 1985 problem 10
Dodao/la:
arhiva2. travnja 2012. Prove that for every point
on the surface of a regular tetrahedron there exists a point
such that there are at least three different curves on the surface joining
to
with the smallest possible length among all curves on the surface joining
to
.
%V0
Prove that for every point $M$ on the surface of a regular tetrahedron there exists a point $M'$ such that there are at least three different curves on the surface joining $M$ to $M'$ with the smallest possible length among all curves on the surface joining $M$ to $M'$.
Izvor: Međunarodna matematička olimpijada, shortlist 1985
Školjka 
