Answer:
Angle A= 135 degrees and Angle B= 45 degrees
Step-by-step explanation:
Supplementary means two angles added together to make 180.
Angle A= 3x and Angle B= x
So 3x +x =180
4x=180 divide both sides by 4
x =45
So Angle A = 3 times 45 =135 degrees
Angle B= the value of x which is 45 degrees