1A50.10 - Radian
Demonstrate what a radian is.
Pull out the cardboard disk and pink string that is cut to the correct length. Make sure that the string is the length of the radius and of the arc length that is imaged on the disk.
A radian is equal to 180/pi (57.3 degrees). It maps out the angle for which the arc length is equal to the radius. With the provided string, show that it is the length of the radius and that it indeed matches the arc length of an arc that traces out 57.3 degrees.