to square100
  forward 100
  right 90
  forward 100
  right 90
  forward 100
  right 90
  forward 100
  right 90
end

to triangle :length
  repeat 3 [forward :length right 120]
end

to square :length
  repeat 4 [forward :length right 90]
end

to csquare :length
   penup
   fd :length/2 rt 90 fd :length/2 ; move to a corner
   pendown
   repeat 4 [fd :length rt 90]
   penup
   fd :length/2 rt 90 fd :length/2 ; move to the center
   pendown
end

to poly :sides :length :color
  setpencolor :color
  repeat :sides [ 
    forward :length 
    right 360/:sides 
  ]
end

to colorpoly :sides :length :color
  setpencolor :color
  poly :sides :length :color
  setfloodcolor :color
  fd :length/2
  rt 90 
  fd :length/2 
  fill
  bk :length/2
  lt 90
  bk :length/2 
end 

to spin :sides :length :step
  ht
  repeat :step [
    poly :sides :length 0
    rt 360/:step
  ]
  st
end

to spiral :sides :num :step
  ht
  repeat :num [ 
    pendown 
    poly :sides 10+(repcount * :step) 0
    penup
    home
    seth repcount * :step
  ]
  pendown
  st
end

to splash :num :radius
  ht
  repeat :num [   
    pendown
    colorpoly 2+(round (random 10)) 10+(round (random 30)) (round (random 7)) 
    penup
    setxy (round (random :radius))-(:radius/2) (round (random :radius))-(:radius/2)
  ] 
  pendown
  st
end