Central and Circumscribed Angles

The vertex of [math]\angle CHB[/math] is located:

inside the circle on the circle at the center of the circle outside the circle

What is the relationship between the central angle ([math]\angle CAB[/math])and the circumscribed angle ([math]\angle CHB[/math])? Move points A, B, and C to test whether the relationship always holds true.

[math]m\angle CAB=\frac{1}{2}\ast m\angle CHB[/math] [math]m\angle CAB=m\angle CHB[/math] [math]m\angle CAB=2\ast m\angle CHB[/math] [math]m\angle CAB+m\angle CHB=180[/math]

Information: Central and Circumscribed Angles