I only know the answer for A. So A+B+C is 180 degrees in all. Since we don't know C yet, we have to add up A and B, which is 87 degrees. Take 180 (the total of the triangle) and subtract 87 which is 93 degrees. So the value of x (C) is 93. Hope this helps, and sorry I don't know b! Been trying to look for an answer lol. :)