pls help I'll mark the first person brainliest answer all

Answer:
4
a. 12
b. 8
c. 30
d. 40
Step-by-step explanation:
each exterior = 360/n
30*n=360
divide both side by 30
Answer is 12
The same apply to others to 4d
so first its 4
a. 12
b. 8
c. 30
d. 40
i will try to explain:
each exterior = 360/n
30*n=360
divide both side by 30
Answer is 12
The same apply to others to 4d