Answer:
C
Step-by-step explanation:
The exterior angle of a triangle is equal to the sum of the 2 opposite interior angles.
10x + 2 is an exterior angle of the triangle, thus
10x + 2 = 8 + 6x + 34 = 42 + 6x ( subtract 6x from both sides )
4x + 2 = 42 ( subtract 2 from both sides )
4x = 40 ( divide both sides by 4 )
x = 10
Thus
∠ S = 8 + 6x = 8 + 6(10) = 8 + 60 = 68° → C
