code for diagrams

> circ:=plot([sin(t),cos(t),t=0..2*Pi],scaling=constrained,thickness =1,color=blue,xtickmarks=[],ytickmarks=[]):
rad1:=plot([[0,0],[1,0]],thickness=2,color=black):
arr:=plot([.5*cos(t),.5*sin(t),t=0..Pi/3.1],thickness=3):
pts:=plot({[0,0], [cos(Pi/3),sin(Pi/3)]},style=POINT,thickness=3):
hed:=plot([[.5*cos(Pi/3.1),.5*sin(Pi/3.1)] ,[.5*cos(Pi/3.1),.4*sin(Pi/3.1)]],thickness=3 ):
rad2:=plot([[0,0],[cos(Pi/3),sin(Pi/3)]],thickness=2,color=black):
thet:=plots[textplot]([.3,.1, theta],font=[TIMES,BOLD,16],color=black):
pt:=plots[textplot]([1.2*cos(Pi/3),1.2*sin(Pi/3),`(x,y)`],font=[TIMES,BOLD,16]):
IO:=plots[textplot]([1.2,.1,`(1,0)`],font=[TIMES,BOLD,16],align = ABOVE):
plots[display]([IO,pt,hed,arr,pts,circ,rad1,rad2,thet]);