There are hundreds of remaining Sangakus, see references at wasan site.

There are many very hard Sangakus, and they often involve tough calculations. One of the simplest, although interesting, is to inscribe two squares and a circle in a larger circle.

The problem is mainly to find

Find a condition relating a and b to R.
Solution

Give a simple relation for radius ρ.
Solution

Find a construction of the figure.

Conversedly, given the two circles, construct the squares.

Details (with JavaSketchpad applets)