Puzzle of the Week #222 - Staircase Rings

In the following diagram, the ‘staircase’ is made up of horizontal and vertical lines of equal length. The ends of these lines determine the radius of each of the rings, whose shared centre is the end of the final horizontal line.

If the overall shape has an area of 100, what is the area of each of the individual regions A to G?

STAIRCASE RINGS.JPG