Respuesta :

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