Answer: (B) - 55
Explanation: We have a hexagon, albeit irregular.
Since it is a six-sided shape, we know that the angle sum of a hexagon is 720°, using the angle sum formula, 180 · (n - 2), where n represents the number of sides.
Thus, we can say that the angles have to add up to 720°
Now, we know the missing side inside the hexagon has to be (180 - x), since x and the missing angle join to make a straight line (in other words, they are supplementary).
Now, we can say:
(180 - x) + 115 + 130 + 115 + 130 + 105 = 720
775 - x = 720
-x = 720 - 775 = -55
x = 55
