In this article, Teachers use "studio" time to review videotaped classroom episodes, learn about students' developmental levels in geometry, and increase students' use of mathematical language and vocabulary.This article has a twofold purpose: (1) to share the power of opening the classroom door to a community of professional learners through "studio" sessions so that teachers might grow in their collective knowledge regarding the teaching and learning of mathematics, and (2) to share what a group of second grade students taught teachers about teaching geometry. The lessons discussed in studio formed the basis of this article and were primarily designed in collaboration with the consultant, coach, and studio teacher, although certain aspects of the lesson, such as opportunities for student discourse, involved the entire community. (A bibliography is included.)