Angles Formed by Secants and Tangents Investigation
Drag the endpoints of the arcs to see how the measure of the angle DEB changes.
What is the relationship between the arc measures and the angle measures? Use data from the applet above to support your answer (time permitting).
Move points A and D together such that segment AE is tangent to the circle. Do NOT move points C and B together yet. What is the relationship between the arc measures and the angle measures? Use data from the applet above to support your answer (time permitting).
Leave A and D together and now move points C and B together such that segment CB is tangent to the circle. What is the relationship between the arc measures and the angle measures? Use data from the applet above to support your answer (time permitting).