BIG Circle questions

Hey guys I have a quiz on this material on Friday. It's a bunch of the formulas in one big circle. There are answers on the bottom, but I dont get how they got it. Can someone please help me by giving me the formulas to get the answer?

For example I know Angle 7 and 5 equal 1/2(AD+BC)

and 4 and 6 is equal to 1/2(AB+CD)