polygons [3]
Geometric plane figures with several sides and a number of equal angles.
regular hendecagon 
Polygon with 11 (hendeca = eleven) sides and equal angles.
regular dodecagon 
Polygon with 12 (dodeca = twelve) sides and equal angles.
regular decagon 
Polygon with 10 (deca = ten) sides and equal angles.
regular nonagon 
Polygon with nine (nona = nine) sides and equal angles.
regular octagon 
Polygon with eight (octo = eight) sides and equal angles.