Answer:
If the sum of a triangle equals 180 degrees we’ll go off of that by doing this.
(7x+8)+(5x+2)+(7x-1)=180
7x+8+5x+2+7x-1=180
19x+9=180
19x=180-9
19x=171
19x/19=171/19
x=9
With that let’s find each angle,
I’ll just label them A, B, C.
A: (7x+8)
7(9)+8
63+8=71
B: (7x-1)
7(9)-1
63-1=62
C: (5x+2)
5(9)+2
45+2=47
71+62+47=180