Drawing a Box with rlineto

%!
%% Draws a one square inch box and inch in from the bottom left
%% This example uses relative coordinates on the lines

/inch {72 mul} def	% Convert inches->points (1/72 inch)

newpath			% Start a new path
1 inch 1 inch moveto	% an inch in from the lower left
1 inch 0 inch rlineto	% bottom side
0 inch 1 inch rlineto	% right side
-1 inch 0 inch rlineto	% top side
closepath		% Automatically add left side to close path
stroke			% Draw the box on the paper
showpage		% We're done... eject the page