Step-by-step explanation:
ok so as u know the angles of a triangle add up to 180.
So we will be using that for help.
S+R+T=180
12x+13x+12x-4+2-3=180
37x-5=180
37x=185
x=5
Now we will plug in the value for x to find each angle
S= 13(5)-4
=61
T=12(5)-3
=57
R=12(5)+2
=62
Hope this helped:)
