Abstract:
Let $n$ be an odd positive integer. It is proved that if $n+2$ is a power of a prime number and $\gamma$ is a regular closed non-self-intersecting curve in $\mathbb R^n$, then $\gamma$ contains vertices of an equilateral $(n+2)$-link polyline with $n+1$ vertices lying in a hyperplane. It is also proved that if $\gamma$ is a rectifiable closed curve in $\mathbb R^n$, then $\gamma$ contains $n+1$ points that lie in a hyperplane and divide $\gamma$ into parts one of which is twice as long as each of the others. Bibl. – 5 titles.
Key words and phrases:Shnirel'man's theorem, equilateral polyline.