Theorem based on circle

Topic:
Circle
Consider the circle with centre A. CD is a chord of the circle. Move the positions of C or D to change the length of CD . Observe the values of CE and DE. What can you say about E? What is AE? What happens to the measure of the angle AED as you change the length of CD? Move the position of A to change the radius of the circle. Repeat the experiment. What do you observe? Frame the theorem based on your Observation.