Acircle with radius of 9 cm sits inside a circle with radius of 11

Ok so to answer this, we first need to figure out the area of both circles
we will use the formula A=πr²

so our two areas end up being 121π and 81π

now all we do is subtract the smaller from the larger

121π - 81π = 40π

shaded region = 40π

Here are the answers to the ones that i could see.