Answer:
The strategy is to find out the total area and find the area of the 3 circles then subtract the sum of the circles' are from the total area
Total area = (length * width) = ( 3+6+9+12) * 18 = 540 sq. inch
3 Circles area = πr₁² + πr₂² + πr₃²
- r₁= 12/2 = 6 in
- r₂ = 9/2 = 4.5 in
- r₃ = 6/2 = 3 in
πr₁² + πr₂² + πr₃²
π(6²) + π(4.5)² + π(3)²
= 36π + 20.25π + 9π
= 65.25π
Shaded area = 540 - 64.25π = 335.011 sq. in
