Title: Acute sets,
Abstract: A set of points in $\mathbb{R}^d$ is acute, if any three points from this set
form an acute triangle. In this note we construct an acute set in
$\mathbb{R}^d$ of size at least $1.618^d$. Also, we present a simple example of
an acute set of size at least $2^{\frac{d}{2}}$.