Answer:
25*pi or
78.5 square units.
Explanation:
If there was no shaded area, the area of the circle would be pi * r^2
r = 10
Area = pi * 10^2
Area = 100 * pi
Since there is a shaded area, the shaded part looks to be 1/4 of the whole. There's no indication of what it actually is, but 1/4 should be close enough.
Area_shade = 1/4 (100*pi)
Area_shade = 25 * pi
That's one answer.
Another is 25 * 3.14 = 78.5 square units