- twisted loop
A Mobius band can be made from a strip of paper. It is given a twist before its ends are glued together. A half twist results in one side and one edge. If it is cut in half (between the red and green lines) two joined loops are formed.
To New
# set default screen, pen and turtle values
ResetAll SetScreenSize [400 400] HideTurtle
SetSC Black SetPC Green SetPS 1 PenUp
End
To Mobius :Twist
For [Angle 0 359 5] [
Home Up :Angle
Forward 200 Down 90 LeftRoll :Twist*:Angle
Paddle
RightRoll :Twist*:Angle Up 90 Back 240 Wait 4]
End
To Paddle
# draw perpendicular red/green paddle
Right 90 Back 60
SetPW 8 SetPC Red PointStart Dot Pos PointEnd
SetPW 1
SetPC Red PenDown LineStart Forward 60 LineEnd PenUp
SetPC Green PenDown LineStart Forward 60 LineEnd PenUp
SetPW 8 SetPC Green PointStart Dot Pos PointEnd
Back 60 Left 90
End
To Go :Twist
New Perspective CS PenUp
HideTurtle SetSC Black
Mobius :Twist/2
Message [View3D?] View3D
End