How do you find the symmetry type of a pattern? Easy: by answering at most
four questions, starting with this one:
Will the pattern coincide with itself if it is rotated around some center?
Is there a reflection?
Is there a glide-reflection?
Is there a glide-reflection in an axis that is not a reflection axis?
Is there a reflection?
Is there a glide-reflection?
Are there reflections in two directions?
Parallel mirrors & glide (pmg)
Are all rotation centers on reflection axes?
Perpendicular mirrors & glide (cmm)
Is there a reflection?
Are there reflections in two directions?
Three rotations & mirrors (p31m)
Is there a reflection?
Are there four reflection axes?
Quarter-turns & rotated mirrors (p4g)
Quarter-turns & mirrors (p4m)