9514 1404 393
Answer:
60°
Step-by-step explanation:
The sum of angles in a quadrilateral is 360°. The interior angle adjacent to x will have measure 180°-x. So, the equation can be written ...
100° +50° +90° +(180° -x°) = 360°
420° -x° = 360° . . . . simplify
x = 420 -360 . . . . . . divide by °, add x-360
x = 60
