Answer:
x = 48°
Explanation:
The sum of the interior angles of a quadrilateral = 360°
Subtract the sum of the 3 given angles from 360 for fourth angle
fourth = 360° - ( 30 + 108 + 90)° = 360° - 228° = 132°
The fourth angle and x are adjacent angles and are supplementary, thus
x = 180° - 132° = 48°