Answer:
b. 75°
Step-by-step explanation:
By exterior angle theorem:
3x = x + 70°
3x - x = 70°
2x = 70°
x = 70°/x
x = 35°
Therefore, 3x = 3*35° = 105°
[tex] \measuredangle ACB= 180\degree - 105\degree [/tex]
(Linear pair angles)
[tex] \measuredangle ACB= 75\degree [/tex]
