Answer:
A ≈ 530 cm²
Step-by-step explanation:
The swept area equals the total area covered by the blade minus the unswept area.
The area of a sector with radius r and angle θ is:
A = (θ / 360) πr²
So the swept area is:
A = (θ / 360) πR² − (θ / 360) πr²
A = (θ / 360) π (R² − r²)
A = (150 / 360) π (21² − 6²)
A ≈ 530 cm²
