Answer:
nonagon, concave
Step-by-step explanation:
This shape is considered a nonagon - it has 9 straigh lined sides. It's also concave since one of the lines 'caves' in and isn't a copmple 180.
About 15.3%!
ill explain in comments, i hope this helps you out
20+5x=
so we can't do anything with this, what is the task