http://i42.tinypic.com/rh78u0.jpg

Ok basically i can figure out this equation from this info which is:

8 x (sin a°/2) = 6 x (sin b°/2)

I got the above equations by using the chord length formula as both circles share a similar chord length.

It is pretty much two simultaneous equations subbed into each other.

not sure how to go about solving this though

All help is appreciated