Answer:
I do not understand very well but they are already helping me
Step-by-step explanation:
80
........
..
the answer is 80
21 V³ 15- 9V³15
= (21-9)V³15
= 12V³15
Each exterior angle of a regular 25-gon = 360/25 = 14.4 deg. and each interior angle= 165.6 deg.
