Answer:
1. 40π/3
2. 18π
Step-by-step explanation:
For the first shaded region.
OA = OC
OD = OB
=> OA = 3+4 = 7 => R = 7
=> Circle area = π·7^2 = 49π
120/360 = 1/3 => The area of shaded region + mini region is (1/3)·49π = 49π/3
The area of white mini region with radius 3 is (1/3)·π·3^2 = 3π
=> The area of the shaded region is 49π/3 - 3π =
= 40π/3
For the second shaded region:
R = 9 cm.
Circle area = π·9^2 = 81π
80/360 = 2/9
=> The area of the shaded region is (2/9)×81π = 18π
