Formula for Area of Overlapping Rings?

[jpg15]

Could anyone direct me to a formula for the area enclosed by two overlapping rings? Sketch below...

Thanks...
-jg

 

[jpg15]

I realize my question was a little bit ambiguous... specifically, the area in terms of the radius of the two circles and the distance between their centers. The rings are identical.

Sorry about that.
-jg

 

[HallsofIvy]

Also, looking at your attachment appears to require a password.

 

[jpg15]

OK, should be fixed now. Sorry, once again.
-jg