Answer: 55 degrees
Step-by-step explanation:
To find the measure of angle A, you first have to find x. To do that you use this equation: 80+(3+6x)+(7x+6)=180. You then simplify that equation.
80+(3+6x)+(7x+6)=180
80+3+6x+7x+6=180
89+13x=180
13x=180-89
13x=91
x=91/13
x=7
Then you plug x into the expression for angle A.
7x+6
7*(7)+6
49+6
55
Angle A=55 degrees
