Answer:
12. 108 degrees
13. 150 degrees
15. 40 degrees
16. 30 degrees
Step-by-step explanation:
12. 540 is the total degrees inside a pentagon, and since it is regular (every side is equal) you divide 540/5 to get 108
13. 1800 is the total degrees inside a dodecagon, and since it is regular (every side is equal) you divide 1800/12 to get 150
15. 1260 is the total degrees inside a nonagon however since it is asking for the exterior angle you take 1260/9 to get 140 and since every straight line is 180 degrees you subtract 140 from 180 to get 40 degrees.
16. 1800 is the total degrees inside a 12-gon (dodecagon) however since it is asking for the exterior angle you divide 1800/12 to get 150 degrees which since every straight line is 180 you subtract 150 from 180 to get 30 degrees.
