Answer:
282.7 cm²
Explanation:
Hello There!
To find the area of the shaded area we are going to want to find the area of the whole semi circle and subtract it by the area of the smaller semi circle
To find the area of a semicircle we use this formula
where r = radius
For the large semi circle
The radius of the larger semi circle is 18 cm so we plug in 18 into r in the formula
So..
So the area of the whole semi circle is 508.9380099 cm²
Now to find the area of the smaller semi circle
The radius for the smaller semi circle is 12 cm so we plug in 12 into r in the formula
so the area of the smaller semi circle is 226.1946711cm²
Finally we want to subtract the area of the smaller semi circle from the area of the whole semi circle
508.9380099 - 226.1946711 = 282.7433388
Finally we want to round to the nearest tenth and we get that the area of the rainbow is 282.7 cm²