p3
Three-fold rotations only. Centers in three different locations.
From Kathy Paur:
![p3-1](p3-1.jpg)
p3m1
Mirrors in three directions.
Three-fold rotation centers in three different locations.
From Kathy Paur:
![p3m1-1](p3m1-1.jpg)
p31m
Mirrors in three directions.
Three-fold rotation centers in two different locations.
From Kathy Paur:
![p31m-1](p31m-1.jpg)