a. 40
b. 50
c. 60
d. 140

Answer:
ans: option D
Step-by-step explanation:
exterior angle of triangle is equal to sum of opposite interior angle I.e
angle ACD= angle CAB + angle ABC
Answer:
d
Step-by-step explanation:
The exterior angle of a triangle is equal to the sum of the 2 opposite interior angles.
∠ ACD is an exterior angle of the triangle, then
∠ ACD = 80° + 60° = 140° → d