Relationship between central and inscribed angles
This is about how you can realize the relationships between center angle and inscribed angle in terms of same arc that they see. You can move the points on the circle in order to see relationship of the angles.
What will be changed if you move point E or point C? Do you realize that relationship between central and inscribed angle? What if point D and point B are moved? Are there any changes in angle CDE and angle CBE?