The relationship of arcs is: S '/ S = ((2/5) * pi * r) / (2 * pi * r) Rewriting we have: S '/ S = ((2/5)) / (2) S '/ S = 2/10 S '/ S = 1/5 Therefore, the area of the shaded region is: A '= (S' / S) * A Where A: area of the complete circle: A '= (1/5) * 100 * pi A '= 20 * pi Answer: The area of the shaded region is: A '= 20 * pi