The green square has area of 4.
The center blue circle is tangent
to each of the other blue circles,
which are tangent to the green square.
Let the radius of the center circle be R,
and the radius of the other circles be r.
Write r as a function of R.
What fraction of the area of the square
is covered by the circles?
What value of R gives all 5 circles
the same area?
