Answer:
≈ 41.1 cm²
Step-by-step explanation:
The shaded area (A) is calculated as
A = area of sector - area of Δ ABC
= πr² × [tex]\frac{90}{360}[/tex] - ( [tex]\frac{1}{2}[/tex] × 12 × 12 )
= π × 12² × [tex]\frac{1}{4}[/tex] - (6 × 12)
= 144π × [tex]\frac{1}{4}[/tex] - 72
= 36π - 72
≈ 41.1 cm² ( to 1 dec. place )