It always helps to draw a picture.

You can have the second circle be centred anywhere on the first, I've just chosen the point

.

It's important to note that the equations of the circles are

and

.

By subtracting the first equation from the second we find

.

So the equations intersect at

.

Putting the equations as

in terms of

gives:

and

.

Since these are symmetrical about the

axis, we can work out the areas enclosed by the above semicircles, and then double it.

So we can finally say:

You will need to use trigonometric substitution to solve these.

Try

for the first

and

for the second.