Here is how I did it:
Draw a square around a green circle in which the circle is perfectly inscribed inside the square.
Find the area of the square, and the area of the circle.
Subtract the area of the circle from the area of the square. The number you get is equal to the area of the central blue part in the picture of your problem.
Then find the area of the blue circle.
Add those values together, and that should be your answer.
Also, for number 1. This is how far I got.
Using the properties of a median through a centroid, I found OB through pythagorean theorem
I also found AO through median properties
Notice that AOB is a right angle through supplements.
I you used pythagorean theorem to find AB?
Notice triangles AOB and ZOB are similar.
Since it is a median, we know that the triangles ZOB and AOB are in a ratio of 1:2, respectively. I also know the area of AOB because base and height are known.
So, how would I find OZ?