A hatch mark, also called a hash mark or tick mark, is a short stroke used to indicate geometric congruence or a position on a graduated scale. Line segments marked with the same number and style of strokes have equal lengths (Florida Department of Education, p. 14). Separate groups can be distinguished by one, two, or three strokes. The number of strokes does not specify a length or a ratio of lengths, and different marking patterns alone do not assert unequal lengths.
Hatch marks can also be drawn across the circular arcs of angle markers to indicate congruent angles. Matching numbers of strokes indicate equal angle measures (Fallow and Griffiths 2009, p. 30).
On a graduated real line or coordinate axis, tick marks indicate positions or scale values (Rose).
