Answer: 593.46 mm²
Explanation:
The diameter of the big circle is 2(7) + 20 = 34
divide the diameter by 2 to get the radius (r) = 17
Area = π·r²
= π(17)²
= 289 π
The diameter of the big circle is 20
divide the diameter by 2 to get the radius (r) = 10
Area = π·r²
= π(10)²
= 100 π
The area of the shaded region is the difference between the area of the big circle and the area of the small circle.
= 289 π - 100 π
= 189 π
= 189(3.14)
= 593.46