Imagine: Angles Fan

[list=1][*]Can you find angles in this situation?[/*][*]If you increase the blue angle, what is happening to the green angle?[/*][*]If you double the blue angle, what is happening to the green angle?[/*][*]If you make the blue angle into half, what is happening to the green angle?[/*][/list]

Information: Imagine: Angles Fan