I have found this in a Facebook group :) The only thing we are given is the marked distance and we need to find the shaded area. I have tried several options but I am always missing some data. Then I tried the following: I considered two different conditions:
The two side circles do not overlap; they are tangent to each other. In this case, the given distance corresponds to 3 diameters, so each is 3.33 units and the requested area is 100 sq. units.
The two side circles overlap by 100%. Again the area is 100 sq. units.
It is therefore obvious that the area is independent from the amount of overlapping, i.e. from the angle of the specific line segment to the horizontal line.
Can you provide a geometrical solution? Many thanks!!