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
.
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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 $M'$.
Školjka