Answer:
0.49 m²
Step-by-step explanation:
The area (A) is calculated using A = πr² ( r is the radius )
A = external area - internal area
external radius = [tex]\frac{1.2}{2}[/tex] = 0.6
internal radius = [tex]\frac{0.9}{2}[/tex] = 0.45
A = π(0.6² - 0.45²)
= π(0.36 - 0.2025) = 0.1575π ≈ 0.49 m²