Pasted

set size square 1,1
 set multiplot
set size 1,1
set origin 0,0
 set xrange [ -3.10000 : 3.10000 ]
set yrange [ -3.10000 : 3.10000 ]
 set parametric
set trange [0:2*pi]
plot sin(t), cos(t) notitle
 set trange [-4:4]
plot 0,t notitle
plot t,0  notitle
 b=1.0
plot b,t notitle
plot -b,t notitle
plot t,b notitle
plot t,-b notitle
 c=sqrt(3.0)
d=3.0
 set trange [-d:d]
plot c,t notitle
plot -c,t notitle
plot t,c notitle
plot t,-c notitle
 set trange [-c:c]
plot d,t notitle
plot -d,t notitle
plot t,d notitle
plot t,-d notitle
  c=.5
d=sqrt(3.0/4.0)
 set trange [-d:d]
plot c,t notitle
plot -c,t notitle
plot t,c notitle
plot t,-c notitle
 set trange [-c:c]
plot d,t notitle
plot -d,t notitle
plot t,d notitle
plot t,-d notitle
 unset parametric
a = tan( pi/6.0)
plot x*a notitle
plot x/a notitle
plot -x*a notitle
plot -x/a notitle
 unset multiplot