Answer:
pi × 18cm^2
Or approximately,
56.52cm^2 (using 3.14 for pi)
or
56.5487cm^2 (using pi button on calculator)
Step-by-step explanation:
Area of a circle is pi times [radius squared].
All circles are 360°.
Problem can be solved by finding area of whole circle, and then using ratios.
Whole Circle: area = pi × (9cm)^2 = pi × 81cm^2
80° / 360° = Area[shaded] / (pi × 81cm^2)
pi × 18cm^2 = Area[shaded]
((If you read my answer before the edit, I am sorry. I made a calculator error.))
