Your teacher will wait at least 10 minutes for you, if they haven't heard from you. If you're going to be later than that it's a great idea to let them know by sending a chat message right in the classroom, or via the Classroom - Messages page.
If you want your teacher to wait longer
If you'd like your teacher to wait longer than average for you, please discuss this with your teacher. We can help facilitate this discussion if you'd like, although we've found student/teacher discussing this directly is usually best; please contact your learning coach if you'd like our help facilitating this discussion.