Answer:
1. No, not all line segments
2. Yes, quadrilateral
3. Yes, hexagon
4. No, it is not a closed shape.
1. Hexagon, concave
2. Octagon, convex
3. Pentagon, concave
4. Triangle, convex
5. No, not a closed shape
6. Yes
7. No, not all line segments
8. Yes
9. Uploaded in picture
10. Yes, both have exactly four sides
11. Four
12. C. 3