Answer:
Depends on how the teacher wants the answer:
400π (in terms of pi) or 1256.6 (rounded to tenths place)
Explanation:
40/2 = 20, the radius of one of the blue circles
Use the formula: πr², but divide it by 2 because it is a semicircle
π20² = 400π = 1256.63706
Let me know if you need help rounding it if the question asks you to.