In this video the teacher initates a discussion about worksheet 1 and angle measure.
Object of an Angle, Clip 1, 3:07
The students initially are unsure what the problem is asking for
Thus the teacher leads a discussion about what the activity is asking for. He is allowing the students to give what their thoughts about the activity are.
At one point the teacher focuses on a student contribution aboout needing an "accurate distance measurement" and allows her to speak. When she mentions they need the same degree, the teacher changes her wording to be the same angle measure. Thus he is using (and consequently showing he values) the student contributions, but he is also ensuring they begin to use the appropriate language.
He notices the students are having difficulty describing the angle so the teacher draws a diagram to help the students. They are able to point out which angle they are referring to. This may be a necessary move as the students may believe they already know what an angle is and may not see the point of the questioning.