Sum of supplementary angles = 180
so <A and <B are supplementary angles so <A + <B = 180
<B is 30 more than <A so that means <B = <A + 30
Lets x = the measure of angle A
<A = x
<B = x + 30
Now
x + x + 30 = 180
2x + 30 = 180
2x = 150
x = 75
So
<A = 75°
<B = 75° + 30 = 105°
Answer
<A = 75°
<B = 105°
