a = 49
You find this by adding 109 and 30, then subtracting from 180.
b = 55
c = 55
we know that the place where the two lines meet has to be 360, so we subtract the two 109s from it. Divide the answer by 2. This number is added to 54 and subtracted from 180. This gives us 55. c is in a position that equals 55.
