Affixes

Across

3. Unbearable
5. Unicycle
6. Bicycle
8. Decagon
10. Irresponsible
12. Pentagon
13. Triangle

Down

1. Octangular
2. Quadrangle
4. Misunderstand
7. Illogical
8. Disrepair
9. Century
10. Impossible
11. Insensible