In mathematics a line plays many roles -- as in this fine poem (which is a sonnet, more or less).
Lines by Martha Collins
Draw a line. Write a line. There.
Stay in line, hold the line, a glance
between the lines is fine but don't
turn corners, cross, cut in, go over
or out, between two points of no
return's a line of flight, between
two points of view's a line of vision.
But a line of thought is rarely
straight, an open line's no party
line, however fine your point.
A line of fire communicates, but drop
your weapons and drop your line,
consider the shortest distance from x
to y, let x be me, let y be you.
"Lines" is found in Some Things Words Can Do, (Sheep Meadow, 1998).