2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/143220We prove that every connected triangle-free graph on $n$ vertices contains an induced tree on $\exp(c\sqrt{\log n})$ vertices, where $c$ is a positive constant. The best known upper bound is $(2+o(1))\sqrt n$. This partially answers questions of Erdos, Saks, and Sos and of Pultr.Combinatorics05C55, 05C05text