All angles in the diagram are measured to the nearest degree. Then 59° could actually be something between 58.5° and 59.5°. Analogously, 108° is between 107.5° and 108.5°, and 81° is between 80.5° and 81.5°
The addition of the four angles must be equal to 360°
The upper bound (the maximum possible value) of x is then: