The answer is b 60 degrees <span />
Answer:
20 sides
We know that if we find the size of an exterior angle for the given regular polygon whose exterior angle is 18∘, we can find the number of sides. Where, n is the number of sides. Therefore, there are 20 sides in the given regular polygon whose exterior angle is 168∘.
The average of the first three is 83 (85 + 90 + 74)/3
The average of the next 3 is 86.
The difference is 3
