Answer:
A
Step-by-step explanation:
The shaded area is the area of the outer circle - the area of the inner circle.
the radius of the outer circle r₁ = 40 ÷ 2 = 20m
The radius of the inner circle is r₂ = 15 cm, thus
shaded area = πr₁² - πr₂²
= π(20² - 15²) = π(400 - 225) = 175π ≈ 549 → A
