Circles

Hey guys I have a few questions to ask you guys.

I have quadrilateral that has the angle measures: 130, 92, and 70. It asks me if Ia circle can be circumscribed in there. How do I know if it can or can't?

Now I need help with these Imageshack - asdjw.jpg
I'm supposed to find the indicated arc or angle measure. For the first on how would I find arc AB and the second how do I find angle A?

Thanks for your help guys.


Also I was wondering has anyone ever done those big,bigger,biggest circle puzzle? I would like to double check my answers with anyone if possible.

In the figures, what are 101, 120 and 98? What is point C?

I don't know what point C is it's just there, but the number 101 is the angle measure and the others are arc measures.