Intersecting lines & vertically opposite angles

You are given line segment AB with point E on it. You may move points A, B and E. The measure of angle DEB can be adjusted by moving the slider labeled α, and angle AEC can be adjusted by the β slider. Move the points and the sliders around to see how they effect the image. Come up with some observations. 1. What affect does moving Points A or B have on the image? 2. What effect does point E have? 3. What happens when you move slider α? 4. What happens when you move slider β? 5. When α = β, what do you notice? What is formed? 6. Is your observation in #5 ALWAYS true? 7. What conclusion can be made based off your observation?