Answer:
Step-by-step explanation:
The angles of a quadrilateral have to add up to equal 360. That means that
1x + 2x + 3x + 4x = 360 and
10x = 360 so
x = 36. Then
2x = 72 and
3x = 108 and
4x = 144
Angle A and angle D are opposite angles, as are angles B and C. This is because opposite angles are supplementary.