The angles on the inside of a trianlge must add up to 180°. So we take what we know and go from there.
180-106=74
Angles A and B must equal 74 so we can write an equation: (3y+22)+4y=74
Drop parenthesis and combine: 3y+22+4y=74
7y+22=74
Subtract 22 from both sides: 7y+22-22=74-22
7y=52
Divide by 7: 7y=52/7
I would leave it as a fraction and plug it in for y. The you only have to round once. Angle A- 4(52/7)=208/7=29.7...
Angle B- 3(52/7)+22=156/7=22.3...+22=44.3
So... Angle A: 29.7°
Angle B: 44.3°
Angle C: 106°
106+29.7+44.3=180
So our numbers are correct. (I rounded to the tenths but you could go out more if you'd like.
