Answer: 879.20 km²
Step-by-step explanation:
The diameter of the big circle is 2(10) + 18 = 38
divide the diameter by 2 to get the radius (r) = 19
Area (A) = π·r²
= π(19)²
= 361π
The diameter of the small circle is 18
divide the diameter by 2 to get the radius (r) = 9
Area (A) = π·r²
= π(9)²
= 81π
The area of the shaded region is the difference between the big circle and the small circle.
[tex]Area_{shaded}=A_{big}-A_{small}[/tex]
= 361π - 81π
= 280π
= 280(3.14)
= 879.20
