Calculating the area of a triplet of circles.

Question

I have an image of the problem which is quite self-explanatory.

Any ideas?

Answer 1

$\pi x=$ area of $3$ equal pieces. So area of one piece$=\pi x/3$.

Now notice that

area of one piece= Area of a sector of a circle which has a central angle of $\pi /3$ rad$= r^2 \pi/6$.