See circle C below. You can adjust the length of the radius using the slider. 1. Move point A along the circle. Does the length of the radius ever change? What does moving A do? 2. Move points B or D along the circle. Does the length of the diameter ever change? What does moving B or D do? 3. Move point C. How does this affect the circle? 4. Adjust the radius. What happens to the diameter when the radius is adjusted? How are they related?