Step-by-step explanation:
9x+6+5x+90°= 180°
14x+96=180
14x=180-96
14x=84
x= 84/14
x=6
so, <A=5x=5(6)=30°
<B=9x+6=9(6)+6=54+6=60°
<C = 180-(30+60)=180-90=90°
