Answer:
116°
Step-by-step explanation:
3x-4+9x+17+6x-31=180
18x-18=180
+18 +18
18x=198
18x/18=198/18
x=11
a=9x+17
a=9(11)+17
a=99+17
a=116°
hopefully this helps :)
Angle A : 116°
The sum of all the angles in the triangle is 180°
∠A+∠B+∠C=180°
[tex]\tt 9x+17+3x-4+6x-31=180\\\\18x-18=180\\\\18x=198\\\\x=11\\\\A=9.11+17=116^0[/tex]
