File:Nonagon annotated.svg

; Created in LibreOffice 4 with this LibreLogo program.
 ; Usage: Put this code into an English language document in LibO Writer,
 ; and click on the Start icon of the View»Toolbar»Logo toolbar.
 FONTSIZE 22 FONTFAMILY “Nimbus Sans L”
 FOR vertices IN [3, 4, 5, 6, 8, 9, 10, 12, 15, 18, 20] [
 ;     PICTURE “regular_polygon_%d_annotated.svg” % vertices [ ; from LibO 4.1.1
     PICTURE [
 	HOME CLEARSCREEN HIDETURTLE
 	FILLCOLOR “WHITE” PENCOLOR “SILVER” 
 	PENDOWN PENSIZE 2 CIRCLE 400
 	β = 360/vertices
 	CIRCLE [80 + vertices * 10, 80 + vertices * 10, 0, β]
 	FONTCOLOR “SILVER”
 	IF vertices >= 18 [ f = 0.011 ] [ f = 0.013 ]
 	HEADING β*0.57 PENUP FORWARD (80 + vertices * 10) * (0.23 + (f * vertices))
 	HEADING 0 LABEL “%d°” % β
 	HOME HEADING 0 PENDOWN
 	dots = []
 	REPEAT vertices [
 		FORWARD 200
 		where = POSITION
 		dots = dots + [where]
 		BACK 200 RIGHT β
 	]
 	HOME
 	PENSIZE 2 CIRCLE 10
 	PENCOLOR “BLACK” FONTCOLOR “BLACK”
 	α = ((vertices-2)/vertices)*180
 	PENUP FORWARD 200 PENDOWN
 	CIRCLE [90 + 105/vertices, 90 + 105/vertices, 180 – α/2, 180 + α/2]
 	PENUP BACK 20 + 70/vertices LABEL “%d°” %  α
 	HOME PENUP PENSIZE 4 PENUP
 	FOR i IN dots + dots[0:1] [ POSITION i PENDOWN ] PENSIZE 2
 	FOR i IN dots [ PENUP POSITION i PENDOWN CIRCLE 10 ]
 	HOME HEADING  β * 1.5 PENUP FORWARD 201
 	HEADING 0 CIRCLE 22 TEXT “s”
     ]
 ]