perpendicular http://projects.lib.rochester.edu/lsf-asl/wp-content/uploads/2015/07/perpendicular.webm
permanent http://projects.lib.rochester.edu/lsf-asl/wp-content/uploads/2015/07/permanent_continuous.webm
perfect, perfection http://projects.lib.rochester.edu/lsf-asl/wp-content/uploads/2015/07/perfect.webm
