The coordinate grid shows three points P, Q, and R:
A four-quadrant coordinate grid from negative 10 to positive 10 in increments of 2 is drawn. Point P is plotted on the ordered pair negative 8, negative 8. Point Q is plotted on the ordered pair negative 8, negative 4. Point R is plotted on the ordered pair 6, negative 4.
The distance between Q and R is ______ units.
