The measure of all the angles in a triangle is 180°
So put all the angles into an equation like so:
180=55+(7x+1)+(6x-6)
Gather the x's
7x+6x=13x
180=55+13x+1-6
Then add/subtract
55+1-6=50
180=50+13x
Then get the X alone by subtracting 50 from both sides
180-50=50-50+13x
130=13x
Divide 13
130÷13=10
x=10
Then you put the answer that you got for x into the problems
Angle T: (6(10)-6)=54
Angle G: (7(10)+1)=71
So the answer is B) 54°
Hope this helps! :)