Worksheet 5, Clip 2, Discussion of Question 1, part II,0:49
The teacher makes the decision to ask about how many kilometers is Pi/2 radians.Since the radius in this problem is 1, the angle measure in radians is also the distance in kilometers. This gives a simple situations where the students can orient themselves. The radius will be changed in subsequent problems.
Note that it is still important to make sure the students realize that they should multiply their radius by their angle measure, even when it is 1. This will help with their understanding of radians.