Answer:
The outering is 11 cm so let's see what the Area is. We use the formula Area of a circle:
A = πr² = πd2/4
If:
Radius, r = 11 cm
Then:
Diameter, d = 22 cm
Circumference, C = 69.115038378975 cm
Area, A = 380.13271108436 cm²
now all we need to do is subtracts the inner circle Area.
If:
Radius, r = 9 cm
Then:
Diameter, d = 18 cm
Circumference, C = 56.548667764616 cm
Area, A = 254.46900494077 cm²
Thus: 380.13271108436 cm² - 254.46900494077 cm² =
125.6637061436 cm²
Step-by-step explanation:
