So in this problem, we have to find the hypotenuse first, since sine is opposite over hypotenuse.
We can do this using the pythagorean theorem (you can search it if you don't know). Or, we can just remember this as one of our pythagorean triplets (9,40,41). The last side will be 41.
We have to find the value of sin(D)
opposite/hypotenuse = 9/41 = 0.2195 which is about 0.22
