Become familiar with the interface. Play with the sliders and checkboxes to get an understanding of how things work.[br]Before continuing, reset the applet by pressing the icon in the upper right corner.

(1) Determine at what angle (in degrees) the arc length from B to C is equal to the radius: ______[br][br](2) Definition: radians is a unit of angular measure, similar to degrees. One radian is equal to an angle at the center of a circle whose arc is equal in length to the radius. Thus, from (1), we can conclude: 1 radian ≈ ______ degrees (set θ equal to the angle above and click the checkbox for “Show radian measure?” to verify).[br][br](3) Change the radius to different values. How does it affect the radian measure? What is the relationship between the arc length and the radian measure?[br][br](4) What is the degree measure of the angle that creates a semicircle? _______ What is the radian measure of the same angle? ________[br][br](5) What is the degree measure of the angle that creates a full circle? _______ What is the radian measure of the same angle? ________[br][br](6) Set the radius to 1 and click the checkbox for “Show Circumference?” Look at a few different angles and make a hypothesis on the relationship between radian measure and circumference.[br][br](7) Recall the radian measure for a full circle: ________ What is the circumference when the radius is 1? ________[br][br](8) From (7), make a conclusion about how many radians are in a full circle.