C.supplementary is the right one
The answer is 8.8
You have to use SohCahToa to figure out the length of AB
As you know 30/45 = 6/9
So a = 9 makes the equation true
In order for a triangle to exist, the two smaller sides must add to a number greater than the largest side.
So, 13+10 = 23
So, the number has to be smaller than 23, and the largest whole number less than 23 is 22.
22 Is the largest possible whole number.