Answer:
122
Step-by-step explanation:
1. to calculate the value of the internal angles use the formula (n - 2) x 180
n = number of sides.
(6 - 2) x 180 = 720
The sum of the interior angles should be 720
2. Then, all you have to do is plot an equation and solve for X
129 + 107 + 131 + 115 + 116 + X = 720
X = 720 - 598
X = 122
