The opposite of an angle around a point is always the same, so we know the unlabelled angle is also worth 43. Then, do 43 + 43 which is 86. Next, note that angles around a point all add up to 360. What we need to do is find the total of c and b, which is 360 - 86. Therefore, 274 is the total of b and c. Finally, half 274 to find both individual values. That means b = 137 and c = 137